Troubleshooting Bluetooth Keyboard

hi folks,

I’m trying to connect my bluetooth keyboard to my OSMC on raspberry 3. Sometimes, the device is visible (but I’m unable to connect to it) and sometimes, it’s not visible. I’m bringing the keyboard into pairing mode, though (and I see the pairing LED light up).

In the kodi.log (/home/osmc/.kodi/temp/kodi.log), I see this line when I try to connect to that device:
2019-09-02 23:03:59.499 T:1687704288 ERROR: EXCEPTION: Non-Existent Control 300

I tried to remove the device completely with “remove” and I deleted the bluetooth cache in /var/lib/bluetooth//cache/* but that didn’t solve the problem.

I know, that in the past, I had it connected for a short while but then, the troubles re-appeared.
And I have this keyboard twice and if it is defective, then both are defective equally.

how do you troubleshoot bt devices in osmc? and how can I completely reset the bluetooth functionality? maybe that helps…