Hello @SchBenedikt
With the Linux desktop client the files synchronize normally. Cloudflare etc. I’m not using. The problem occured some days ago. Before that downloading files in the NextCloud app worked fine.
@JimmyKater the thread here WARNING Nextcloud Android client version 3.28.1 deletes user data Revert back to 3.28.0 (F-Droid) - #12 by Oclair mentions that a 0-Bytes problem will be fixed with the next version 3.28.2. I currently have 3.28.1, so I’ll wait. Thank you for that. I searched the forum before, maybe not good enough. That does not excuse your attitude though. This world is already negative enough, no need for that. You can say the same thing you said in a nice way.