NC Client. Endless loop after server update


The day before yesterday my Nextcloud (running on a UCS server from the app catalogue) was updated from 18.0.7-0 to 19.0.3-0.
After that the NC server could not access my external memory (SMB shares) because smbclient was missing.
After this was installed it works.

After this update my laptop with installed NC client:

Ubuntu 20.04
NC 2.6.2

has performed a complete resynchronization. After a few hours it was finished. Since then the file sync runs in a kind of endless loop.

How can I fix this?

with best