Check your server logs to see if there are any clues there. What version of the Server are you running and what version of the app is installed on your Android?
Yes, I’ll agree. But, 2.2.1 is the stable version. I had asked him about the version he was using, but never got an answer. If he is using 2.2.2 or 2.2.3, he should be fine by reverting to 2.2.1. I was about to add more info to my last comment regarding Android, as well. Version 8.X (Oreo), Contacts backup doesn’t work. I’m thinking that photo sync probably won’t either, but I have not yet tried it.
Uploading with 2.2.1 and Oreo, however, works fine for me.
Author of seafile client seems to insist that “it won’t build and that’s that”, which is “less than ideal”. Updating from the webpage is cumbersome and there is no autoupdate…