Cannot re-pair Bluetooth Keyboard when wrong pairing code is entered

[Grace Icay]

Expected behavior:
1. Pressing the “Cancel” button during device pairing should close the pairing code prompt
2. Re-pairing BT keyboard after cancelling initial pairing should re-open the pairing code prompt

Problem:
1. Pressing the “Cancel” button during device pairing does not close the pairing code prompt
2. Re-pairing BT keyboard after cancelling initial pairing does not show the pairing code prompt.

Steps:
1. Turn on the system’s Bluetooth (usually turned on by default on boot)
2. Try to pair the system with the BT Keyboard via the Bluetooth Settings UI
3. When the pairing code prompt appears, input the wrong code and press enter. This should generate a new code
4. Press “Cancel” on the pairing code prompt. Notice that the cancel button is not working.
5. Press the Esc button on the system’s keyboard. This should close the pairing code prompt.
6. Try re-pairing the system with the BT Keyboard via the Bluetooth Settings UI.
7. Notice that the connection is loading but the pairing code prompt does not reappear. The system and the BT keyboard cannot be re-paired.

Workaround:
1. When a new code is generated in Step 3, input the correct code. This would successfully pair the system and the BT keyboard.
2. Try rebooting the system after Step 7 to recover the connection.

Notes:
- Keyboards tested:
          > ThinkPad Compact Bluetooth Keyboard
          > Microsoft Designer Keyboard
- Issue does not happen in Windows OS
- I have reported this issue to Intel and they didn't see any error from the connection logs. We are suspecting that this has to do with the Bluetooth UI instead.
- Bluez version: 5.53
- Ubuntu version: 20.04

[Grace Icay (gicay)]

I'm attaching the captured btsnoop logs

[Grace Icay (gicay)]

I'm attaching the dmesg result

[Sebastien Bacher (seb128)]

Thank you for taking the time to report this bug and helping to make Ubuntu better. This particular bug has already been reported and is a duplicate of bug 1845163, so it is being marked as such. Please look at the other bug report to see if there is any missing information that you can provide, or to see if there is a workaround for the bug. Additionally, any further discussion regarding the bug should occur in the other report. Feel free to continue to report any other bugs you may find.