Spastic Primary Menu Action After 3.8 Update

Today when I tried to update my primary menu with a description change for one of the items, I ended up with a server timeout. When my menu came back it had truncated the last 20 or so items from the bottom of the list.

When this happened in the past I repaired the database and then redid the menu. Ugh. This time I optimized the database and added an item. It took.

However, I now have to go into customize my theme and choose from a dropdown everytime I make a change. And even after it has accepted a change, it then reverts back to an older, corrupt menu version and displays a message on my site telling me to choose a menu.

Again, that’s resolved when I now go into the theme customization and choose rather than just save the menu. But whenever I add to my existing menu it does not save changes anymore, and I have just spent a lot of time rebuilding the menu just to have it not save it.

Anyone? Thanks.