Strange problem with my 4iiii Precision Gen3 power meter

Hi all. I have a strange problem with my power meter. Just two weeks back I set it up to show the cadence, and it stayed at 0 rpm when stationary. Now, for the last week or two the cadence is no longer 0. I’ve tried zero offsetting it, to no avail. Is there a problem with the Zwift software that’s causing this? Power seems to be accurately measured. Maybe someone else has or had the same problem and fixed it?