Could it be that the BBS server is creating some sort of virtual device that jus doesn‘t work prperly?
Try disabling any non standard SW to see if there really is a problem with your system or just with 3rd party SW.
You were of course right by this assumption. And now that you say it, it's quite obvious.
DLG mounts devices for each node. TN0:, TN1: etc.
I guess I need to either find a way of excluding them from the Volumes-list or simply not use it. Since BBS:ing is the prime use of my machine unfortunately "not run the application" is not an option. ;)
Thank you for the help and sorry for being stupid!