Library does not sync (Failed to get fs id list)

I wanted to sync my library to a second system. However, the seafile client always shows a network error for my main library. If I create a new library, it is syncing perfectly.

Installing Seadrive, I get the following logs:

[09/24/23 10:25:36] Cloning repo Meine Bibliothek(602eb119-2642-4c13-8eae-70183fc033b2).
[09/24/23 10:25:36] Repo 'Meine Bibliothek' sync state transition from 'synchronized' to 'downloading'.
[09/24/23 10:25:36] Download with HTTP sync protocol version 2.
[09/24/23 10:25:36] Transfer repo '602eb119': ('normal', 'init') --> ('normal', 'check')
[09/24/23 10:25:37] Transfer repo '602eb119': ('normal', 'check') --> ('normal', 'commit')
[09/24/23 10:25:37] Transfer repo '602eb119': ('normal', 'commit') --> ('normal', 'fs')
[09/24/23 10:25:48] libcurl failed to GET https://seafile.zinn-sys.de/seafhttp/repo/602eb119-2642-4c13-8eae-70183fc033b2/fs-id-list/?server-head=132a43e563a6d25a5dd3b320e9b9640aba9a3fc6&dir-only=1: Transferred a partial file.
[09/24/23 10:25:48] Failed to get fs id list for repo 602eb119 on server https://seafile.zinn-sys.de.
[09/24/23 10:25:48] Transfer repo '602eb119': ('normal', 'fs') --> ('error', 'finished')
[09/24/23 10:25:48] Repo 'Meine Bibliothek' sync state transition from downloading to 'error': 'Error occured in download.'.

The error occurs across different systems. However, on my initial system, where I have been syncing everything for month, Seafile has no issues with syncing. The newly installed Seadrive client still shows the same error.

Running seaf-fsck, I do not get any error and I can access everything via the web interface.

My library is 180 GB big.

that’s pretty self explanatory
do you get any error if your run curl -v https://seafile.zinn-sys.de/seafhttp/repo/602eb119-2642-4c13-8eae-70183fc033b2/fs-id-list/?server-head=132a43e563a6d25a5dd3b320e9b9640aba9a3fc6&dir-only=1?

are you able to run a curl to https://seafile.zinn-sys.de/seafhttp/ or even ?