Now with timestamps..
At 21:53:19 I wwitched the monitor on again to do something on the PC and the bluetooth mouse was gone again.
Then I stopped and started bluetooth. Then the mouse was back.
  
❯ stdbuf -oL bluetoothctl -- scan on | ts
Feb 18 14:44:56 Discovery started
Feb 18 14:44:56 [CHG] Controller A0:9F:10:BE:79:E4 Discovering: yes
Feb 18 14:44:56 [NEW] Device 3A:1A:52:FD:4F:69 ET-5150 Series
Feb 18 14:44:57 [NEW] Device 04:A2:22:29:ED:4A RX-V685 29ED47 Bluetooth
Feb 18 15:12:23 [DEL] Device 3A:1A:52:FD:4F:69 ET-5150 Series
Feb 18 15:12:23 [DEL] Device 04:A2:22:29:ED:4A RX-V685 29ED47 Bluetooth
Feb 18 20:32:38 [CHG] Device D4:25:00:7D:6A:5A ServicesResolved: no
Feb 18 20:32:38 [CHG] Device D4:25:00:7D:6A:5A Connected: no
Feb 18 21:53:59 [CHG] Controller A0:9F:10:BE:79:E4 Class: 0x003c0104 (3932420)
Feb 18 21:53:59 [CHG] Controller A0:9F:10:BE:79:E4 UUIDs: 0000110e-0000-1000-8000-00805f9b34fb
Feb 18 21:53:59 [CHG] Controller A0:9F:10:BE:79:E4 UUIDs: 00001200-0000-1000-8000-00805f9b34fb
Feb 18 21:53:59 [CHG] Controller A0:9F:10:BE:79:E4 UUIDs: 00001132-0000-1000-8000-00805f9b34fb
Feb 18 21:53:59 [CHG] Controller A0:9F:10:BE:79:E4 UUIDs: 00001133-0000-1000-8000-00805f9b34fb
Feb 18 21:53:59 [CHG] Controller A0:9F:10:BE:79:E4 UUIDs: 0000110c-0000-1000-8000-00805f9b34fb
Feb 18 21:53:59 [CHG] Controller A0:9F:10:BE:79:E4 UUIDs: 00001800-0000-1000-8000-00805f9b34fb
Feb 18 21:53:59 [CHG] Controller A0:9F:10:BE:79:E4 UUIDs: 0000112f-0000-1000-8000-00805f9b34fb
Feb 18 21:53:59 [CHG] Controller A0:9F:10:BE:79:E4 UUIDs: 00001801-0000-1000-8000-00805f9b34fb
Feb 18 21:53:59 [CHG] Controller A0:9F:10:BE:79:E4 UUIDs: 00001106-0000-1000-8000-00805f9b34fb
Feb 18 21:53:59 [CHG] Controller A0:9F:10:BE:79:E4 UUIDs: 0000180a-0000-1000-8000-00805f9b34fb
Feb 18 21:53:59 [CHG] Controller A0:9F:10:BE:79:E4 UUIDs: 00001104-0000-1000-8000-00805f9b34fb
Feb 18 21:53:59 [CHG] Controller A0:9F:10:BE:79:E4 UUIDs: 00001105-0000-1000-8000-00805f9b34fb
Feb 18 21:53:59 [CHG] Controller A0:9F:10:BE:79:E4 UUIDs: 00005005-0000-1000-8000-0002ee000001
Feb 18 21:53:59 [CHG] Controller A0:9F:10:BE:79:E4 Class: 0x001c0104 (1835268)
Feb 18 21:53:59 [CHG] Controller A0:9F:10:BE:79:E4 UUIDs: 0000110e-0000-1000-8000-00805f9b34fb
Feb 18 21:53:59 [CHG] Controller A0:9F:10:BE:79:E4 UUIDs: 00001200-0000-1000-8000-00805f9b34fb
Feb 18 21:53:59 [CHG] Controller A0:9F:10:BE:79:E4 UUIDs: 00001132-0000-1000-8000-00805f9b34fb
Feb 18 21:53:59 [CHG] Controller A0:9F:10:BE:79:E4 UUIDs: 00001133-0000-1000-8000-00805f9b34fb
Feb 18 21:53:59 [CHG] Controller A0:9F:10:BE:79:E4 UUIDs: 0000110c-0000-1000-8000-00805f9b34fb
Feb 18 21:53:59 [CHG] Controller A0:9F:10:BE:79:E4 UUIDs: 00001800-0000-1000-8000-00805f9b34fb
Feb 18 21:53:59 [CHG] Controller A0:9F:10:BE:79:E4 UUIDs: 0000112f-0000-1000-8000-00805f9b34fb
Feb 18 21:53:59 [CHG] Controller A0:9F:10:BE:79:E4 UUIDs: 00001801-0000-1000-8000-00805f9b34fb
Feb 18 21:53:59 [CHG] Controller A0:9F:10:BE:79:E4 UUIDs: 00001106-0000-1000-8000-00805f9b34fb
Feb 18 21:53:59 [CHG] Controller A0:9F:10:BE:79:E4 UUIDs: 0000180a-0000-1000-8000-00805f9b34fb
Feb 18 21:53:59 [CHG] Controller A0:9F:10:BE:79:E4 UUIDs: 00001104-0000-1000-8000-00805f9b34fb
Feb 18 21:53:59 [CHG] Controller A0:9F:10:BE:79:E4 UUIDs: 00001105-0000-1000-8000-00805f9b34fb
Feb 18 21:53:59 [CHG] Controller A0:9F:10:BE:79:E4 UUIDs: 00005005-0000-1000-8000-0002ee000001
Feb 18 21:53:59 [CHG] Controller A0:9F:10:BE:79:E4 Class: 0x00180104 (1573124)
Feb 18 21:53:59 [CHG] Controller A0:9F:10:BE:79:E4 UUIDs: 0000110e-0000-1000-8000-00805f9b34fb
Feb 18 21:53:59 [CHG] Controller A0:9F:10:BE:79:E4 UUIDs: 00001200-0000-1000-8000-00805f9b34fb
Feb 18 21:53:59 [CHG] Controller A0:9F:10:BE:79:E4 UUIDs: 00001132-0000-1000-8000-00805f9b34fb
Feb 18 21:53:59 [CHG] Controller A0:9F:10:BE:79:E4 UUIDs: 00001133-0000-1000-8000-00805f9b34fb
Feb 18 21:53:59 [CHG] Controller A0:9F:10:BE:79:E4 UUIDs: 0000110c-0000-1000-8000-00805f9b34fb
Feb 18 21:53:59 [CHG] Controller A0:9F:10:BE:79:E4 UUIDs: 00001800-0000-1000-8000-00805f9b34fb
Feb 18 21:53:59 [CHG] Controller A0:9F:10:BE:79:E4 UUIDs: 0000112f-0000-1000-8000-00805f9b34fb
Feb 18 21:53:59 [CHG] Controller A0:9F:10:BE:79:E4 UUIDs: 00001801-0000-1000-8000-00805f9b34fb
Feb 18 21:53:59 [CHG] Controller A0:9F:10:BE:79:E4 UUIDs: 00001106-0000-1000-8000-00805f9b34fb
Feb 18 21:53:59 [CHG] Controller A0:9F:10:BE:79:E4 UUIDs: 0000180a-0000-1000-8000-00805f9b34fb
Feb 18 21:53:59 [CHG] Controller A0:9F:10:BE:79:E4 UUIDs: 00001104-0000-1000-8000-00805f9b34fb
Feb 18 21:53:59 [CHG] Controller A0:9F:10:BE:79:E4 UUIDs: 00001105-0000-1000-8000-00805f9b34fb
Feb 18 21:53:59 [CHG] Controller A0:9F:10:BE:79:E4 UUIDs: 00005005-0000-1000-8000-0002ee000001
Feb 18 21:53:59 [CHG] Controller A0:9F:10:BE:79:E4 Class: 0x00100104 (1048836)
Feb 18 21:53:59 [CHG] Controller A0:9F:10:BE:79:E4 UUIDs: 0000110e-0000-1000-8000-00805f9b34fb
Feb 18 21:53:59 [CHG] Controller A0:9F:10:BE:79:E4 UUIDs: 00001200-0000-1000-8000-00805f9b34fb
Feb 18 21:53:59 [CHG] Controller A0:9F:10:BE:79:E4 UUIDs: 00001132-0000-1000-8000-00805f9b34fb
Feb 18 21:53:59 [CHG] Controller A0:9F:10:BE:79:E4 UUIDs: 00001133-0000-1000-8000-00805f9b34fb
Feb 18 21:53:59 [CHG] Controller A0:9F:10:BE:79:E4 UUIDs: 0000110c-0000-1000-8000-00805f9b34fb
Feb 18 21:53:59 [CHG] Controller A0:9F:10:BE:79:E4 UUIDs: 00001800-0000-1000-8000-00805f9b34fb
Feb 18 21:53:59 [CHG] Controller A0:9F:10:BE:79:E4 UUIDs: 0000112f-0000-1000-8000-00805f9b34fb
Feb 18 21:53:59 [CHG] Controller A0:9F:10:BE:79:E4 UUIDs: 00001801-0000-1000-8000-00805f9b34fb
Feb 18 21:53:59 [CHG] Controller A0:9F:10:BE:79:E4 UUIDs: 00001106-0000-1000-8000-00805f9b34fb
Feb 18 21:53:59 [CHG] Controller A0:9F:10:BE:79:E4 UUIDs: 0000180a-0000-1000-8000-00805f9b34fb
Feb 18 21:53:59 [CHG] Controller A0:9F:10:BE:79:E4 UUIDs: 00001104-0000-1000-8000-00805f9b34fb
Feb 18 21:53:59 [CHG] Controller A0:9F:10:BE:79:E4 UUIDs: 00001105-0000-1000-8000-00805f9b34fb
Feb 18 21:53:59 [CHG] Controller A0:9F:10:BE:79:E4 UUIDs: 00005005-0000-1000-8000-0002ee000001
Feb 18 21:54:02 [CHG] Controller A0:9F:10:BE:79:E4 Class: 0x00500104 (5243140)
Feb 18 21:54:02 [CHG] Controller A0:9F:10:BE:79:E4 UUIDs: 00001133-0000-1000-8000-00805f9b34fb
Feb 18 21:54:02 [CHG] Controller A0:9F:10:BE:79:E4 UUIDs: 0000110e-0000-1000-8000-00805f9b34fb
Feb 18 21:54:02 [CHG] Controller A0:9F:10:BE:79:E4 UUIDs: 00001105-0000-1000-8000-00805f9b34fb
Feb 18 21:54:02 [CHG] Controller A0:9F:10:BE:79:E4 UUIDs: 00001132-0000-1000-8000-00805f9b34fb
Feb 18 21:54:02 [CHG] Controller A0:9F:10:BE:79:E4 UUIDs: 00001200-0000-1000-8000-00805f9b34fb
Feb 18 21:54:02 [CHG] Controller A0:9F:10:BE:79:E4 UUIDs: 00001104-0000-1000-8000-00805f9b34fb
Feb 18 21:54:02 [CHG] Controller A0:9F:10:BE:79:E4 UUIDs: 00005005-0000-1000-8000-0002ee000001
Feb 18 21:54:02 [CHG] Controller A0:9F:10:BE:79:E4 UUIDs: 0000110c-0000-1000-8000-00805f9b34fb
Feb 18 21:54:02 [CHG] Controller A0:9F:10:BE:79:E4 UUIDs: 00001801-0000-1000-8000-00805f9b34fb
Feb 18 21:54:02 [CHG] Controller A0:9F:10:BE:79:E4 UUIDs: 0000112f-0000-1000-8000-00805f9b34fb
Feb 18 21:54:02 [CHG] Controller A0:9F:10:BE:79:E4 UUIDs: 0000110b-0000-1000-8000-00805f9b34fb
Feb 18 21:54:02 [CHG] Controller A0:9F:10:BE:79:E4 UUIDs: 0000180a-0000-1000-8000-00805f9b34fb
Feb 18 21:54:02 [CHG] Controller A0:9F:10:BE:79:E4 UUIDs: 00001800-0000-1000-8000-00805f9b34fb
Feb 18 21:54:02 [CHG] Controller A0:9F:10:BE:79:E4 UUIDs: 0000111f-0000-1000-8000-00805f9b34fb
Feb 18 21:54:02 [CHG] Controller A0:9F:10:BE:79:E4 UUIDs: 0000110a-0000-1000-8000-00805f9b34fb
Feb 18 21:54:02 [CHG] Controller A0:9F:10:BE:79:E4 UUIDs: 00001106-0000-1000-8000-00805f9b34fb
Feb 18 21:54:02 [CHG] Controller A0:9F:10:BE:79:E4 UUIDs: 0000111e-0000-1000-8000-00805f9b34fb
Feb 18 21:54:02 [CHG] Controller A0:9F:10:BE:79:E4 Class: 0x00700104 (7340292)
Feb 18 21:54:02 [CHG] Controller A0:9F:10:BE:79:E4 UUIDs: 00001133-0000-1000-8000-00805f9b34fb
Feb 18 21:54:02 [CHG] Controller A0:9F:10:BE:79:E4 UUIDs: 0000110e-0000-1000-8000-00805f9b34fb
Feb 18 21:54:02 [CHG] Controller A0:9F:10:BE:79:E4 UUIDs: 00001105-0000-1000-8000-00805f9b34fb
Feb 18 21:54:02 [CHG] Controller A0:9F:10:BE:79:E4 UUIDs: 00001132-0000-1000-8000-00805f9b34fb
Feb 18 21:54:02 [CHG] Controller A0:9F:10:BE:79:E4 UUIDs: 00001200-0000-1000-8000-00805f9b34fb
Feb 18 21:54:02 [CHG] Controller A0:9F:10:BE:79:E4 UUIDs: 00001104-0000-1000-8000-00805f9b34fb
Feb 18 21:54:02 [CHG] Controller A0:9F:10:BE:79:E4 UUIDs: 00005005-0000-1000-8000-0002ee000001
Feb 18 21:54:02 [CHG] Controller A0:9F:10:BE:79:E4 UUIDs: 0000110c-0000-1000-8000-00805f9b34fb
Feb 18 21:54:02 [CHG] Controller A0:9F:10:BE:79:E4 UUIDs: 00001801-0000-1000-8000-00805f9b34fb
Feb 18 21:54:02 [CHG] Controller A0:9F:10:BE:79:E4 UUIDs: 0000112f-0000-1000-8000-00805f9b34fb
Feb 18 21:54:02 [CHG] Controller A0:9F:10:BE:79:E4 UUIDs: 0000110b-0000-1000-8000-00805f9b34fb
Feb 18 21:54:02 [CHG] Controller A0:9F:10:BE:79:E4 UUIDs: 0000180a-0000-1000-8000-00805f9b34fb
Feb 18 21:54:02 [CHG] Controller A0:9F:10:BE:79:E4 UUIDs: 00001800-0000-1000-8000-00805f9b34fb
Feb 18 21:54:02 [CHG] Controller A0:9F:10:BE:79:E4 UUIDs: 0000111f-0000-1000-8000-00805f9b34fb
Feb 18 21:54:02 [CHG] Controller A0:9F:10:BE:79:E4 UUIDs: 0000110a-0000-1000-8000-00805f9b34fb
Feb 18 21:54:02 [CHG] Controller A0:9F:10:BE:79:E4 UUIDs: 00001106-0000-1000-8000-00805f9b34fb
Feb 18 21:54:02 [CHG] Controller A0:9F:10:BE:79:E4 UUIDs: 0000111e-0000-1000-8000-00805f9b34fb
Feb 18 21:54:02 [CHG] Controller A0:9F:10:BE:79:E4 Class: 0x00780104 (7864580)
Feb 18 21:54:02 [CHG] Controller A0:9F:10:BE:79:E4 UUIDs: 00001133-0000-1000-8000-00805f9b34fb
Feb 18 21:54:02 [CHG] Controller A0:9F:10:BE:79:E4 UUIDs: 0000110e-0000-1000-8000-00805f9b34fb
Feb 18 21:54:02 [CHG] Controller A0:9F:10:BE:79:E4 UUIDs: 00001105-0000-1000-8000-00805f9b34fb
Feb 18 21:54:02 [CHG] Controller A0:9F:10:BE:79:E4 UUIDs: 00001132-0000-1000-8000-00805f9b34fb
Feb 18 21:54:02 [CHG] Controller A0:9F:10:BE:79:E4 UUIDs: 00001200-0000-1000-8000-00805f9b34fb
Feb 18 21:54:02 [CHG] Controller A0:9F:10:BE:79:E4 UUIDs: 00001104-0000-1000-8000-00805f9b34fb
Feb 18 21:54:02 [CHG] Controller A0:9F:10:BE:79:E4 UUIDs: 00005005-0000-1000-8000-0002ee000001
Feb 18 21:54:02 [CHG] Controller A0:9F:10:BE:79:E4 UUIDs: 0000110c-0000-1000-8000-00805f9b34fb
Feb 18 21:54:02 [CHG] Controller A0:9F:10:BE:79:E4 UUIDs: 00001801-0000-1000-8000-00805f9b34fb
Feb 18 21:54:02 [CHG] Controller A0:9F:10:BE:79:E4 UUIDs: 0000112f-0000-1000-8000-00805f9b34fb
Feb 18 21:54:02 [CHG] Controller A0:9F:10:BE:79:E4 UUIDs: 0000110b-0000-1000-8000-00805f9b34fb
Feb 18 21:54:02 [CHG] Controller A0:9F:10:BE:79:E4 UUIDs: 0000180a-0000-1000-8000-00805f9b34fb
Feb 18 21:54:02 [CHG] Controller A0:9F:10:BE:79:E4 UUIDs: 00001800-0000-1000-8000-00805f9b34fb
Feb 18 21:54:02 [CHG] Controller A0:9F:10:BE:79:E4 UUIDs: 0000111f-0000-1000-8000-00805f9b34fb
Feb 18 21:54:02 [CHG] Controller A0:9F:10:BE:79:E4 UUIDs: 0000110a-0000-1000-8000-00805f9b34fb
Feb 18 21:54:02 [CHG] Controller A0:9F:10:BE:79:E4 UUIDs: 00001106-0000-1000-8000-00805f9b34fb
Feb 18 21:54:02 [CHG] Controller A0:9F:10:BE:79:E4 UUIDs: 0000111e-0000-1000-8000-00805f9b34fb
Feb 18 21:54:02 [CHG] Controller A0:9F:10:BE:79:E4 Class: 0x007c0104 (8126724)
Feb 18 21:54:02 [CHG] Controller A0:9F:10:BE:79:E4 UUIDs: 00001133-0000-1000-8000-00805f9b34fb
Feb 18 21:54:02 [CHG] Controller A0:9F:10:BE:79:E4 UUIDs: 0000110e-0000-1000-8000-00805f9b34fb
Feb 18 21:54:02 [CHG] Controller A0:9F:10:BE:79:E4 UUIDs: 00001105-0000-1000-8000-00805f9b34fb
Feb 18 21:54:02 [CHG] Controller A0:9F:10:BE:79:E4 UUIDs: 00001132-0000-1000-8000-00805f9b34fb
Feb 18 21:54:02 [CHG] Controller A0:9F:10:BE:79:E4 UUIDs: 00001200-0000-1000-8000-00805f9b34fb
Feb 18 21:54:02 [CHG] Controller A0:9F:10:BE:79:E4 UUIDs: 00001104-0000-1000-8000-00805f9b34fb
Feb 18 21:54:02 [CHG] Controller A0:9F:10:BE:79:E4 UUIDs: 00005005-0000-1000-8000-0002ee000001
Feb 18 21:54:02 [CHG] Controller A0:9F:10:BE:79:E4 UUIDs: 0000110c-0000-1000-8000-00805f9b34fb
Feb 18 21:54:02 [CHG] Controller A0:9F:10:BE:79:E4 UUIDs: 00001801-0000-1000-8000-00805f9b34fb
Feb 18 21:54:02 [CHG] Controller A0:9F:10:BE:79:E4 UUIDs: 0000112f-0000-1000-8000-00805f9b34fb
Feb 18 21:54:02 [CHG] Controller A0:9F:10:BE:79:E4 UUIDs: 0000110b-0000-1000-8000-00805f9b34fb
Feb 18 21:54:02 [CHG] Controller A0:9F:10:BE:79:E4 UUIDs: 0000180a-0000-1000-8000-00805f9b34fb
Feb 18 21:54:02 [CHG] Controller A0:9F:10:BE:79:E4 UUIDs: 00001800-0000-1000-8000-00805f9b34fb
Feb 18 21:54:02 [CHG] Controller A0:9F:10:BE:79:E4 UUIDs: 0000111f-0000-1000-8000-00805f9b34fb
Feb 18 21:54:02 [CHG] Controller A0:9F:10:BE:79:E4 UUIDs: 0000110a-0000-1000-8000-00805f9b34fb
Feb 18 21:54:02 [CHG] Controller A0:9F:10:BE:79:E4 UUIDs: 00001106-0000-1000-8000-00805f9b34fb
Feb 18 21:54:02 [CHG] Controller A0:9F:10:BE:79:E4 UUIDs: 0000111e-0000-1000-8000-00805f9b34fb
Feb 18 21:54:53 [CHG] Controller A0:9F:10:BE:79:E4 Class: 0x00000000 (0)
Feb 18 21:54:53 [CHG] Controller A0:9F:10:BE:79:E4 Powered: no
Feb 18 21:54:53 [CHG] Controller A0:9F:10:BE:79:E4 Discovering: no
Feb 18 21:54:55 [CHG] Controller A0:9F:10:BE:79:E4 Class: 0x007c0104 (8126724)
Feb 18 21:54:55 [CHG] Controller A0:9F:10:BE:79:E4 Powered: yes
Feb 18 21:54:57 [CHG] Device D4:25:00:7D:6A:5A Connected: yes
Feb 18 21:54:58 [CHG] Device D4:25:00:7D:6A:5A ServicesResolved: yes