This is again one of those things that could (and should) be a feature.
After starting a Play Now!-adventurer in a fresh new world, I went to the temple to join the religion. When I talked to the High Priestess, she bellowed "Praise Are the Day of Sacrifices!", but after I had joined the religion, she told me to "Go with Tequil Wardflies." Turns out she believes in a different god than the religion she is leading.
As we see in this picture here (from the Legend of this High Priestess), these two objects of worship are both human gods. So no megabeast conversion has happened (that was my first guess). It seems like she just became a more enthusiastic follower of Are after she had become the high priestess of Tequil.
What tipped the scale from feature to bug was that it wouldn't make much sense that the high priestess would only reveal her true beliefs to a naked crazy stranger.
On a sidenote, this picture here also shows a missing space after the titan.
On another sidenote, when i was trying to figure this out, I tried to look at the religion "The Faith of Riddling" to make sure what god they were worshipping, but I noticed it wasn't written there. Instead I found out that information by checking the 'related entities' part of one of the religion's first members and saw that Are the Day of Sacrifices wasn't listed there, but Tequil Wardflies was. It would be easier if Legends would tell the object of worship of the religion groups straight away.
I can put a save up if needed.