@Vincent I have the same problem, got disconnected just before the end of stage 6, like on hairpin 3. All the other riders disappeared, I could ride to the end, even got the finish screen, but on saving, the file did not upload from the Apple TV. I submitted everything (Garmin file and photos) with a ticket two days ago to get credit, but no answer yet.
Thanks for sorting this out!
I just got an email that the ride cannot be restored but I will get credit for the stage, so thanks to Zwift support!