@sojab0on
Audio speakers works generally over bluetooth, but audio calls (2 ways audio flux) is not working.
That is a well known issue.
To help with your problem, I can suggest wired headsets. I use the earplug from the PlayStation 4 controller and I'm satisfied with this solution.
But there are other wired solutions... until this bug is fixed.
But old kernel means old bluetooth support, so I'm not convinced it will be fixed soon, but one can hope.