I've had the Graphene theme now for a couple of years, working beautifully. Last night I added a menu subitem as usual and suddenly many subitems are showing up in the header, even for many pages that are private and haven't been touched in months. I've gone back to the Menus page in Appearance and can't find what I changed to make it do this. The menus there look normal except for the fact that not all 10 top-level menus are showing; it stops about 3/4 the way through what used to be there.
I hadn't updated WP in a while so I did that this morning, but it didn't make a difference.
We're a non-profit and today's a big donation day for us, so this is the worst possible timing. Can anyone help?