Perhaps the audio feed is too hot.
Are you using the Blue Voice app to manage the audio feed?
Alternately did you check your audio settings in zoom? (look under Settings/Audio)
There are a number of options there including checking the input levels (including auto levelling)
and handling background noise.
Forgive me if this answer is too basic. I don't know what you have tried.
Another thing to check might be;
if other apps are running on your computer
either tying up your processor
or using up the bandwidth