Merfolk stay underwater?

I completed all the Merfolk Chaperone quests and after part 4 was done all the Merfolk that were above water and staying at the inn have been staying underwater the whole time, I thought they would come back up? I want to keep romancing Semeru, but he’s always in the Merfolk Kingdom and when I go visit him I can’t ask him on a date. Is this a bug? 🧜🏻‍♀️🧜🏻‍♂️