I have the same problem at stage 8 . The first time it’s immediatly crash after I tooked a picture. And the second time for any reason it crash after 21 km.
My TDZ Stage 8 that was started at 7:00 GMT 26 Jan, also has not been accepted. Last uphill I made wihout opponents, but I crossed the finishline and Zwift UI saved ride, supposedly.
I have just competed stage 8 of Tour De Zwift but had numerous issues with avatar just stopping at 7.6 and 15.2 miles. Wahoo kickr was connected so Its not that. Plus now I’ve finished it’s only classing me as doing 13 miles and nothing has uploaded. Fuming!!!