I’m not sure if this is a Zwift related issue or Wattbike (I’ve reported to Wattbike Also) - but the other day I was forced to upgrade the Zwift app, and at the same time I thought “why not” and updated the firmware on the Wattbike to the latest April/Stable release.
Since then, whenever I really get a sprint on - either on an actual sprint or on a very fast decent, the resistance suddenly stops and the wheel on the Wattbike just goes into a free-spin. I can never catch it back up and have to wait for the wheel to slow down, meanwhile my rider is just stopped at the side and I have to begin from zero again.
Having foolishly upgraded the Zwift app and Wattbike at the same time I’ve no way to know which one is causing the issue but I know it wasn’t there before. I’ve done plenty of sprints in the past.