Dektop client Could not find configuration reading directory ""

for maybe a year I have a small issue regarding the configuration of my nextcloud. It is an regularly updated, multiple times backup and restored nc-instance (27.0.0) running on NextcloudPI.

From time to time I get the message Server replied with an error reading directory "" and the client has to be restarted to work properly again. Not sure if it’s only an issue on my user as all other users are rarely used family accounts. If anyone could help me out here I would be very glad.