@ambitiousslab It’s probably PipeWire. AFAIK nobody adjusted the audio pipeline to work there with echo cancellation and noise reduction yet. I wouldn’t consider it suitable for phone use until that happens. It’s not rocket science, PipeWire is actually more flexible than PulseAudio for this kind of stuff, but… someone has to do it. Switching back to PulseAudio and reproducing the config from PureOS (including ALSA UCM profiles) would likely give you much better experience right now.
@ambitiousslab (I have to admit that it’s partially my own fault; I have reworked L5 UCM profiles from the ground up long time ago, but neglected upstreaming them and now there are flawed profiles in upstream repos ☹️)