Try using Bluetoothctl command from terminal. Personally been having connection issues a lot before but it always worked when I tried using Bluetoothctl and not through KDE.

If I remember correctly it’s done this way :

bluetoothctl
power on
agent on
scan on
# (wait for the headset to appear, then use its MAC address in the next command)
connect <MAC_ADDRESS>
trust <MAC_ADDRESS>

Been mostly borked for me at least. It works as getting notified, but gotta manually claim the games.