I don’t want to sound too useless because I don’t have a repro case yet either, but I just wanted to say that isn’t the only one experiencing this - I’ve had the viewmode hotkeys stop working too in 4.16 (unmodified launcher version). Fine after a reboot. Undo also stops working sometimes (which I now realize may just be that the hotkey for it stopped working as well - I’ll test that next time I encounter it).