synchronizing between a Windows-network-share and our Nextcloud

We need your help! :slight_smile:

We are using NC 16 and Win-Client 2.5.1.
Among other things, we are synchronizing between a Windows-network-share and our Nextcloud over the NC-win-Client which is localy installed on the Win10-Clients. So far, everything is working fine.

But, if I change my network-connection from LAN to our WLAN (which is also part of our Domain) and sometime later back to LAN, my NextCloud-Client is deleting a bigger part of my files and folders in the network-share.
The other Sync-Folders (which are not located on a network-share) are NOT affected of this step.
At the same time, my windows error-log is showing the following error seven times (see also the picture):

mrxsmb
139
NC%20Fehler

So this Windows-Event is deciding for the losing/synchronizing the data…

Did anybody of you have a similar issue?
Have you ideas of solutions?

Thanks a lot!
Regards
Chris