Activity not saved right

Yesterday I did a training in the Gran Fondo plan. During warming up I accidentally ended training, but also returned. The training just went on and I finished it. I got a checkbox on the activity in my plan with the distance (49,7 km / 1:54 hours / 1209kcals). That is stil there!

BUT! in my activityfiles (Documents/Zwift/Activities) I only found a file with a 2,54 km ride.
What happened? And can I get my whole activity back so I can upload it to other platforms?

Because of internet connection issues in my garage Zwift also didn’t upload this activity (yet).

I hope this i fixable.

I don’t think it’s fixable. I wouldn’t be surprised if this were related to your Internet connection issues. You might consider using a powerline ethernet adapter if you want stable and fast-enough connectivity to a location too far from your WiFi. They’re available with a WiFi access point on the remote end.