This should work... You might try using Pipewire instead of Pulseaudio:
https://atish3604.medium.com/solved-bluetooth-headset-mic-not-working-detected-in-ubuntu-20-04-86a5236444d0
Can you please run
sudo add-apt-repository ppa:ubuntu-x-swat/updates
sudo apt update && sudo apt full-upgrade
reboot and monitor for more freezing...