PC NC Desktop Client "blocks" general file access while syncing

I need help to stop the NC Desktop Client to “block” general file access while syncing.

All local file operations that lead to a file sync (creating, saving, renaming) seem to block all other actions (copy / paste / drag & drop) within Windows Explorer even with files / folders that are not subject to syncing.
I can only use the Explorer once the syncing is finished.

Strange thing, I use the same NC and the same NC Desktop Client on two different Windows 10 PC (work and private) and only the one at work gives me troubles, so I assume the answer lies within the PC config or other possible task running in the background.

The concerning PC is a DELL Optiplex 7060 with an intel core i5-8500 CPU @3.00 GHz
Win 10 Pro (in German) Version 2004, Buid 19041.508
NC client Version 3.0.2 (Win)

Former Win Updates or Updates of the NC client had no effect to the problem mentioned.

Any help or hint to problem solving is very much appreiciated.