Unable to add courses to My Courses

Since a few days I’m not able to add any courses to My Courses, which is very annoying because I keep having to add them as bookmarks right now. Somehow I can see the button, but when I click it is doesn’t add anything.

I’m also having problems when trying to update the order of my courses. When I drag one, I get an error message saying the reordering couldn’t be saved and on refresh it indeed wasn’t changed. The only thing that does seem to work is deleting courses.

Any help would be greatly appreciated as I can’t find any place to ask support!