Big Sur doesn't allow me to change date/time format in menu bar
Since upgrading to Big Sur, I can no longer change the date/time format in the menu bar.
If I head to System Preferences -> Dock & Menu Bar -> Clock and change any of the date/time layouts then it doesn't reflect in the menu bar. I've rebooted but it's no different. In my case, I prefer a 12 hour clock and so 24 hour was already unticked, with an option for AM/PM (this is how I had it before I upgraded). However, the clock appears in 24 hours. If I untick and re-tick, nothing changes.
I've checked with others who have Big Sur and they're seeing the same thing (although one said it worked for them once but not after that).
MacBook Pro 13″, macOS 11.0