Debian Bluetooth Headset Woes

I’m running Debian 10, but am unable to get my bluetooth headset working in anything but A2DP mode. Obviously that doesn’t allow me to use the microphone.
Anytime I swap over to HSF etc and run sound recorder everything just freezes & no sound input/output is produced in anything else either.

I’ve installed the latest pulseaudio/module-bluetooth and bluez from git and it made no difference. I’ve stuck with latest pulseaudio as it did seem to cure a seemingly random drop in volume (and back up a second later) I noticed across a couple of distros.

Anyone have any suggestions on what I could look into next?

There is a pulseaudio module I had to install a while back, forgot the name.

It wasn’t the pulseaudio-module-bluetooth was it?

Might be, haven’t used mic this time I reinstalled, so haven’t looked at it for quite a while.