Setting Special:UserRights expiration for 1 hour on the dropdown in meta is actually setting it for 3 hours (which isn't an option on it).
(change visibility) 00:03, 23 November 2020 Tks4Fish (S) talk contribs block changed group membership for Tks4Fish (S) from steward to flooder (temporary, until 03:03, 23 November 2020) and steward (Testing possible bug)
I couldn't reproduce this on ptwiki.