Sites failing to update when refreshed, going to "Service unavailable" screen.
Physics, biology, Sci-Fi and Fantasy, Medical, Psychology and Skeptics.
Worldbuilding being an exception went to an "Oops, something bad happened" screen (I was refreshing a particular question).
Main meta has so-far been fine.
I noticed this a few (~15) minutes ago, repeated refreshing a few minutes apart leads to sometimes the error message, sometimes the correct page.
August 03, 2022 | 02:45PM (01:45 PM UTC) Stack Exchange Network Sites has transitioned to Unavailable
Then:
August 03, 2022 | 03:13PM (02:13 PM UTC) Stack Exchange Network Sites has transitioned to Degraded
Something seems up on SE's end, not just local to here, southern UK.