Neo 2 power measurement.

My Tacx neo T2 is paired with Zwift via an apple 4 tv. All software is up to date. I ran my FTP a few times, and all was fine for a while. Now I get wildly variable power readings, even at a steady cadence. I turned on Ergo mode on the Zwift, but that does not help. I cannot keep upon high intensity intervals as I would need a cadence over 150 to hit the power needed for the intervals. Any idea where to start troubleshooting? Has anyone else run into this?