See video in link below. After trying for 40 minutes in Zwift, I opened Rouvy and calibrated through it and that fixed the issue. I’ve concluded that Zwift is the issue.
https://photos.app.goo.gl/dEwfst0eqSWCLIVm2
and
https://photos.app.goo.gl/gyHEr40Un5hLsmrC2