When closing a Cubase project, all plugin windows close automatically and the Hub opens up and has the focus - so you are led to believe you can quit Cubase entirely from there with just one click.
However if the Channel Settings window is open and set to Stereo Out or the Audio Performance window is open they are not closed when exiting. Often they may not be visible because they are behind other windows such as (in my case) File Manager or whatever. The hub can then be closed. You might think that you have quit Cubase at this point - but those two windows are still open and possibly hidden by other applications - requiring you to find them and close them specifically before you can actually quit entirely. (Are there other windows that don’t auto close like this?)
Is this expected behavior by design, if so why? If there are no projects open, I expect that closing the Hub completely closes Cubase down entirely. I find this rather annoying and unnecessary.