Which user did you give rights to? Special:ListUsers doesn't even have content-moderator as a group to list...
Looks like a UCP bug... it also seems like Special:ListUsers is broken too.
You can see the logs that show the user right got granted here: https://apocalypticsouls.fandom.com/wiki/Special:Log?type=rights&user=&page=ThatWeirdArtKid&wpdate=&tagfilter=&subtype=
I would report the bug(s) to FANDOM staff via "Contact us".
Alright, thank you for the help