Thank you but that doesn't seem to be the problem (nor do the instructions actually work: search My PC returns nothing).  Also, I'm not using a multi-user configuration.
My drive is mapped correctly, as it has been for the 5 years I've been using QB.  Somehow QB simply can't see any drives other than C: in the browse window.
I don't think it's an issue relative to Windows 11, because the issue existed for me in Windows 10 as well.