It didn't work and when I tried moving the files back from etc/bluetooth.backup to etc/bluetooth, etc/bluetooth became a text file instead of a folder, I don't know why. So now I have lost my etc/bluetooth folder with all the files in it. Is there anyway to get it back?
Try the following
sudo mv /etc/bluetooth /etc/bluetooth.backup
sudo apt-get install --reinstall bluez
After a reboot check the issue. The /etc/bluetooth directory should be empty now.
If this does not work for you, just move back the bluetoth.backup directory to it's original place.
(or)
Missing Firm-ware could also be an issue and you can fix it with the command
sudo apt-get install linux-firmware
Hope this helps!
Thanks in advance!