Mapping of a nC directory to a network drive is not possible

Hi all.
Have a problem with the nC Client 3.2.1 (and 3.2.0) on Win10 pro 64 bit.

Have a lot of directories on the PC, which are mappted to different directories on three different nC servers. All these directories are not on the local disks of the PC but on a NAS storage.

After the update of clients from 3.0.x to 3.2.1 I can’t add a new mapping from a(ny) server to a NAS-based directory. The message is something like “you don’t have write permissions to this directory” (in German). Directories, which were already mapped before the update are syncing well. However, no new directory mapping can be added. Adding mapping to directories on a local drive are working.
This behavior is apparently independent from the server version. And after downgrading to 3.0.x it is working again, but as soon as I update it to 3.2.x it is reproducible denying to add new directories on the network drive.
Who can help on this?