Basically Bluetooth manager runs separately from networkmanager and re-adds the connection to network-manager on startup.
Once you actually go to bluetooth manager and remove the connection from there, it is then listed in nm-applet as "Unmanaged" until the next reboot where it's gone and stays gone.
Okay, I just found out where this is coming from and how to fix it.
Grepping /var/log/kern.log for part of the connection name (not UID) gave me the answer:
Nov 3 14:13:59 Edge NetworkManager[ 739]: <info> [1478178839.0417] audit: op="connection- delete" uuid="7af23897- 96eb-4c28- 839d-43afc93b20 2c" name="GT-S7560 Network" pid=6913 uid=1000 result="success" 811]: <info> [1478178910.8315] keyfile: add connection in-memory (73f45daf- 36c3-4397- 94f5-5b224b497f eb,"GT- S7560 Network") 811]: <info> [1478178910.8363] bluez: BT device GT-S7560 (00:73:E0:7F:3F:30) added (NAP) 811]: <info> [1478179445.0607] audit: op="connection- delete" uuid="73f45daf- 36c3-4397- 94f5-5b224b497f eb" name="GT-S7560 Network" pid=2381 uid=1000 result="success" 700]: <info> [1478179491.2727] keyfile: add connection in-memory (61cfa658- cb83-49c7- 98fb-3c8a60d7cc bf,"GT- S7560 Network") 700]: <info> [1478179491.2793] bluez: BT device GT-S7560 (00:73:E0:7F:3F:30) added (NAP) 781]: <info> [1478182546.4953] keyfile: add connection in-memory (0cbec96f- e1f0-4889- b721-0cb296192c a8,"GT- S7560 Network") 781]: <info> [1478182546.4990] bluez: BT device GT-S7560 (00:73:E0:7F:3F:30) added (NAP)
Nov 3 14:15:10 Edge NetworkManager[
Nov 3 14:15:10 Edge NetworkManager[
Nov 3 14:24:05 Edge NetworkManager[
Nov 3 14:24:51 Edge NetworkManager[
Nov 3 14:24:51 Edge NetworkManager[
Nov 3 15:15:46 Edge NetworkManager[
Nov 3 15:15:46 Edge NetworkManager[
Basically Bluetooth manager runs separately from networkmanager and re-adds the connection to network-manager on startup.
Once you actually go to bluetooth manager and remove the connection from there, it is then listed in nm-applet as "Unmanaged" until the next reboot where it's gone and stays gone.
Still an usability bug IMO.