Audio cuts out on playback

I have 14.0.0.36 Audition running on a one year old mac book on Catalina 10.15.7

all audio records OK on multi or single track. But during sound testing/checking this audio, I hear the first 5/6 seconds of playback then nothing. I can see the meter bars still moving, and the audio has been recorded. if i save/mixdown the project & playback via other programs, such as Logic or VLC - i can hear everything. If I re-start my MAC - it works perfectly for a few minutes, then cuts out again. Once the audio has cut out, there is no way of hearing it in Adobe until I re-start my MAC, closing & re-opening Audition doesnt work.

I have updated all drivers for my soundcard, and all settings in Audio Hardware are correct

Any ideas?