Potential issue could be the newly introduced noisegate? Increasing the noisegate seems to make the problem worse, even in push to talk mode.
When hearing the problem from a third party perspective, it seems to be fade in and out depending on the proximity of the user to their mic. People with headphone mics don't seem to have much of a problem because the mic is close, and desktop mics have a worse time because they're farther away.
In short: Noisegate might be too aggressive.