Now that the plugin update is done, I've tried reproducing this but it works fine for me.
Svenni77, please try with 10.0.4.3 when it's released (or with 10.0.4.2 + the updated archives plugin now, if you don't want to wait) and see if it still happens.
If it does still happen for you, check which action your drag & drop command is running (copy, move, or something more exotic?) and which type of folder you are dragging into (normal local drive? something else?).