Hmm. Didn't know it was related to Moore but just ported back over there to check. It is the same droning noise that plays in the Royal Meadows outside Moore but once I enter Moore just has the usual town type of song.
In Rosaria, I just went over the entire zone and currently it's in every non-town south of Auldhyl. Silkenstrand, Quietsands, Hawk's Cry Cliff, etc. I know I've heard it in other areas of Rosaria at different points but I can't get that to repeat right now.
For quests, I've been doing all the side quests and none are currently available in any of the 3 areas I can go to. Only thing in the log is the main story "Black Light Burns".
Saving/reloading, updating software, patch yesterday, rebooting PS5, nothing changes it. I guess I'll just have to live with it.