I don't use bluetooth input devides so can't comment on those, but I too noticed regressions in the last month or so with regards to AirPods.

They changed the firmware so that it can "seamlessly" move between devices but 1) it's not seamless at all - I actually disabled the new behavior and 2) I'm pretty sure something else changed regarding Bluetooth because switching between devices manually is slower and less reliable than it used to be before, and I bet this change is also responsible for the issue with input devices that you're seeing.