Sync deselects folder by itself, can't keep up, auto deselect folder

Hi,

using the Nextcloud Desktop Client application on linux (ZorinOS) I have watched odd behavior.

  1. The desktop-client deselects the checkmark for syncing a specific folder by itself from time to time → seems out of random
  2. Because of the out-of-sync, the client thinks the files on the server are outdated/newer and wants me to manually select, what file is newer/older.
    That leads to sometimes many files I have to check.
  3. Changes on serverside aren’t directly visible: I uploaded a file to a folder on the serverside through the webinterface. It’s not directly reflected at the desktop-client-side, even if I manually press the synchronize-button. But it states that all is in sync. It takes some time (~5-30min) before the new files are also at the synced-client.

Some backgrounds may worth noticing:
At first installation of the application, there was a folder sync limit set to 500MB. As one folder overcome this limit, the client-app deselected the checkmark on that folder in the sync-list. After I noticed, I disabled the file-size-limit, checkmarked the folder again and synchronized.
This is currently the target folder, on what the above case happens with auto-deselecting happens.
Besides autostarting the nextcloud client app, I noticed sometimes running 2 instances of the app.

Anyone else have a smiliar experience and knows how to fix this behavior?

Thank you guys very much.
Have a nice day.

Today it happend again.
No idea what causes this:

Next thing is a permission problem with a new file. Something is really odd.