Speaking in a voice channel/voice call in the Linux desktop app causes the volume of my mic to lower by itself

Isn't this exactly how auto-gain works? I always turn that off in Vesktop, Discord, and even in Fluxer because auto-gain is trash. At least on Linux.

Most other voice applications I've used handle autogain internally, like as an effect applied on a copy of the audio source. In my personal opinion, the application should not have an effect on a system-level configuration. If it's a setting available inside of Fluxer, I would expect it to only affect Fluxer.