Ok, well, do you want to use this mic and interface with Cubase or to chat on video calls?
There’s a function in the software where you set if Cubase allows the driver to be released when Cubase is no longer in focus. If you do that you’ll get an either/or scenario depending on the driver. In other words if Cubase is set to release the driver then when Cubase is in focus on your computer it will control the driver and thus access the interface, and when you then switch over to YouTube either via an app or a browser Cubase should release the driver so that app/browser can use it. But that’s still either or and in my experience sometimes a bit “inconsistent”.
If you actually want to use the mic for video calls then I would expect that whatever software you use for the video calls, zoom or hangouts or whatever, will allow you to select that interface as input/output, and you wont’ need to touch Cubase.
PS: In my version of Nuendo “release driver when application is in background” is found in “studio”-“Studio Setup”-“VST Audio System” page toward the top.
In addition to that if you’re on Windows I believe there’s a setting there as well if you access the device through “sound” in “settings”, and then “device properties” and “additional properties” (to the right)… in that pop-up window in the “advanced” tab you can tell the OS if applications can take exclusive control of the device (interface) or not. Maybe try that as well.