After screen lock and unlock, I can't use my bluetooth headset

[borasem]

Here is what happened. I have paired and connected my bluetooth for the first time. I have made couple of changes like changing the priorities of what sound device will be used (System Settings > Multimedia > Audio and Video Tab > Device Preferences > Music Section and there drag my headset to the top). I have also changed the configuration of my device to High Fidelity Playback (A2DP Sink) (System Settings > Multimedia > Audio Volume > Configuration Tab and there changed the profile of my headset to that.)

Until I locked my screen and, while sceen is locked, plugged my laptop to electricity, everything was fine.

After that I couldn't repair the state. I have tried rebooting, repairing the device and changing the settings. My headset just doesn't work anymore, and there is nothing I can do about it. I don't want to reinstall the OS, please help me guys.

I have realized a pattern though. After this happened, I couldn't change the Audio Volume setting to High Fidelity Playback (A2DP Sink). Everytime I clicked on the option, it won't be chosen, instead the OFF option is chosen. However, the other volume option, Headset Head Unit (HSP/HFP), is totally choosable and my headset works like that. But this time voice quality is really really bad.

Please help me guys.!! I use Kubuntu 16.04


Update:
I have discovered that there is also another way to recreate this problem. Just disconnect the bluetooth headset and reconnect it, and there will be the same problem.
I have filed a bug report for this problem. Link

[borasem]

I have fixed the issue. But, still, if I try to recreate the problem the save way, the problem is created again. Here is the steps I have used:

1) Open up the terminal.

2) Enter the directory /var/lib/bluetooth.

3) Make sure to backup everything the the directory.

4) Delete everything in the directory. To be more precise, delete the directory of your device directory whose name is the bluetooth address (an address something similar to MAC address. I don't know its name).

5) Reboot.

6) Repair your device.

[GreyGeek]

Did you post this on https://bugs.kde.org/?

[borasem]

Not yet, but I will do