That's still true. I've tried GNOME boxes, and it gave me the impression of being more of an emulator, rather than a true virtualizer. I won't say more about that, because I'm very happy for those who like Boxes, and it meets their needs.
Your remarkable memory is also correct about my Windows 10 VM. It was a Ring video doorbell that was only supported on a PC by Windows, not Linux. And since the Windows VM was available anyway, I sometimes also used it to read a Nook book. No Linux version of the Nook ebook reader existed, either.
That's all changed -- in fact, Ring no longer supports Windows, just smartphones and tablets. So I probably don't use that Windows VM enough to confirm or deny whether the problems that @Wini-Buh reported now exist. Mostly I just update it regularly, to keep it current in case I ever do want to use it for something.
So, no, I haven't seen any such problems, but that doesn't necessarily mean they don't exist.
