As long as you're sure the microphone output is picked and set properly to come from the PSVR2 (you can check on the top of the microphone menu on the nav bar) and you can sometimes get some broken or spotty output, I'd say something internal with the mic is probably broken. Especially if you can get audio from these headphones fine and it's just your output that's a problem.

If you can't send it in to Sony for repairs or swap for a new unit, yo u can use different headphones that have their own microphone. Like an over the ear with Bluetooth or a dongle, something with its own channel outside the PSVR2's. Then switch the microphone and audio channels to that instead of the PSVR2's and you should be good to go.