Hidden Bar is working on my M1 Max MBP 16" with macOS 14.5. Not an option for me because it can't handle the notch, but the basic functionality works.

Ice ( https://github.com/jordanbaird/Ice ) also works, although it's still missing a lot of stuff and also still doesn't have anything to work around the notch. It's being updated though.

If no app works, then it might be something to do with your setup? Maybe some app you use or some change you've made? Very annoying in any case.