Hi,
I am having the same problem with a dual monitor setup on PC, on both Cubase 9.5 and 10.5.
Cubse 9.5 gives me a blank white window for VST Connect and also the Connect Monitor plugin when I open them. Same but blank black windows on Cubase 10.5.
I have managed to find a workaround but this is a little tiresome. If I put the blank windows on my primary monitor and click “switch to generic editor” in the menu (can still see this), then switch back to “plugin editor”, the window appears as it should. Also works with turning “always on top” on and off
Doing this on the secondary monitor doesn’t work.
(Windows 10, GeForce GTX750Ti, Latest version of VST Connect SE at time of writing 4.0.42.240)