I reported previously that WatchOS 8.x had introduced an interface issue with turning previously defined Alarms off or on. At one point I thought that the problem had been partly addressed, but it turned out to be a false alarm. [heh-heh]
Updating to WatchOS 8.5 (and 8.5.1), I tested the alarm switching and found that Apple appears to have addressed it definitively. Stark, night and day (again, heh-heh) difference in functionality.