Since upgrading to Monterey 12.3, I have experienced serious sound quality issues with my Avantree bluetooth headphones (it sounds like the audio is coming from deep down in a well) along with random disconnects. Oddly, I also noticed that the headphones are not listed as an available output device under Sound within the System Preferences despite the fact that my headphones are connected (as shown in Bluetooth) and the only place sound is coming from. The headphones are connected and they are the active output device, but it no longer appears in System Preferences, the connection drops randomly, and the actual sound is muted in tone with a slight echo reverb.