Postponed workout doesn't upload to Strava

Hi fellow Sufferlandrians,

when executing a postponed workout (I know, I should stick to the plan…), for example a workout I should have done yesterday, I continuously see the "play’ symbol on the screen while the video is playing. The timers and other data at the bottom of the screen are visible and running as usual.

After finalizing the workout, the pop-up window to finish the workout and upload the workout to Strava appears as usual. But after returning to the Passport-Activities tab the time spent on the workout is set to 0:00 and the upload to Strava hasn’t taken place. Manually uploading the workout to Strava using the upload button at the top right of the screen doesn’t give me any result either. In the calendar, the workout is still greyed out and hasn’t turned green.

Is this a bug or am I doing something wrong (apart from actually executing the workout on the scheduled date)?