FWIW, my problem is in the permalinks. I had it set to a custom permalink. When I changed it to one of the defaults the menu links worked again. I don’t know why it worked up until today, though. I think I need an .htaccess file, which I managed to create, but could not figure out how to set permissions for it through GoDayddy,. May call about that tomorrow.
In the meantime, maybe .htaccess if part of your issue? Read about it here: https://www.ads-software.com/support/topic/243954?replies=9
Sorry if that is no help. I’m a WordPress newb.