On Android camera upload fails on larger videos

Hey everyone,
First things first: runnning Seafile on a Raspberrry Pi 3 using nginx
whenever I record some larger videos and seafile starts uploading them when on wifi, the upload fails and starts over and over again.
The Seafile android app always tries to upload 2 files in parallel and constantly fails before finishing the upload.
Manually uploading one vid after the other works fine .
Is there anyway to tell the app to only upload one file at the time? Or anything else I can do?

cheers,
guido