Are you using Gnome? If so, there is a known problem I documented a while back: Crash with Bluetooth headphones after Wireplumber 5.13-1 update
If this is the case, you will need to downgrade wireplumber & libwireplumber until a fix is worked out.
Hmmm…I see you are on KDE, but you might still do a downgrade to see if that “fixes” your problem.
I see your issue involves the same handoff problem. Follow the links in my post to see what is going on.