Odd, although my (cycle) workouts stopped showing last weekend and I needed to reconnect to TP (within Zwift) and then worked fine. May be worth disconnecting and reconnecting.TP has had a server upgrade recently so I wonder if in that process there’s been a tweak to the data formats that’s had an impact.
Are you using new run workouts, or copying old ones?
Technology is great until it becomes too clever. For last 6 months I’ve had an issue where if I create a workout on Garmin Connect Browser and then upload to my FR935 via my phone it won’t work. Yet the workout appears on the garmin App fine, and always used to work. And if I create on the phone app then it’s fine, just fiddly to do compared to browser.