Zoom audio suppressing guitar and voice

I have been using zoom for guitar classes for 3 years. I had the guitar and microphone plugged into an guitar processor which also acts as an audio interface. This was connected to my mac book pro M1 via USB. In zoom the audio interface was selected as mic and speaker. This worked flawlessly for those 3 years. Last week when the classes returned after the summer break i plugged in as usual and zoom is now suppressing the sound of the guitar and voice. Even when i just use the mac microphone and speaker when i test mic i can hear my voice but play the guitar and i will be able to hear the first couple of notes and then its suppressed. The people on the on other end of the line said they couldnt make out what i was saying and the guitar sounded weird. I am fully updated on Mac OS and the zoom app. Nothing has changed. I tried another audio interface and got the same problem. The mac and audio interface work flawlessly in other music apps. Im pulling my hair out at this stage.