I had the same (extreme resistance in Zwift) problem after connecting my Wahoo ROAM to Suito… Tried few hours to fix it, finally found a message in the “Wahoo Elemnt users” Google group describing the exact same problem… Apparently the solution is: Disconnect your Wahoo from the trainer (if possible, don’t connect it again) and start a workout in MyETraining… No need to complete it, start it, pedal a few times, stop it… Now everything will return back to normal.
Long explanation: Redirecting to Google Groups
Hope this saves you a few hours, while Wahoo fixes this bug which seems to be there for at least a year now…