I was part of a local FM net tonight on my Anytone D878UV2 super and as has happened before with strong signals 5+ the audio was dropping in and out even through to signal was S9+. So I swapped for my Baofeng UV-S9 and no much problem.
A few minutes of Googling lead me to Reddit r/amateurradio. There is a setting that is incorrect by default, on on UV2 it is in Menu, Settings, 1-Radio Set, 4-Other Func, 26-No signalSTE, turn this to 1-OFF and you should be fine! I have had this problem since it was released almost a year ago!