Whole Domain Shows Pages Not Found

None of the items in my secondary menu are working on my BLOG sub-domain https://blog.christiangays.com

All of the links to my Members' Blogs show page not found, and the one link that is different, "Blog FAQ's" shows a list of everything in all my categories.

I removed all custom CSS but it didn't change anything.
I deactivated all the plugins that were not network activated and deleted the last two plugins that I installed, however I don't think it's a plugin conflict. It was working fine yesterday and I really haven't done anything to this sub-domain in several days. The only changes I have been making have been with Events+ and it is not active on the BLOG sub-domain.

I've tried removing my functions.php in child theme since I had made some changes to it, deleted an mu-plugin that I had added.

Nothing is bringing back the links. The URLs are all correct. They are just pulling up the wrong page or "not found". I'm stumped.

Would appreciate your help.
Support access is granted.
Thank you!