I am running Mobian Trixie on my PPpro and the phone has been reliable for months. I think it helps that I am running the alternate modem firmware which really helps everything. https://themodemdistro.com (PPpro users, this website has the verified fix if your modem wont boot after you change/upgrade firmware it also has recommendations to tweak the audio quality ALSA levels))
I still get complaints about audio quality form people talking to me but I feel like the audio I am hearing is fine from my PPpro.
I still get complaints about audio quality form people talking to me but I feel like the audio I am hearing is fine from my PPpro.