Hi Ziqiao, my preliminary testing looks good! I tried the first option, calling prepare before startMirroringToCompanionDevice but I got the same problem as before. However waiting until the session is running in workoutSession(_:didChangeTo:from:date :) seems to work like a charm. Will do more testing and run some full workout sessions with the beta testers and ping back with any issues. Thanks!

@blacksun no, I haven't received any updates after submitting the feedback report. Do you have same issue?

@blacksun no updates on this issue yet...Do you have the same problem?