I'm also having this issue. I'm worried my current save might be borked and I'll have to either start a new one, or go back several saves.
When did you first notice this happening? If you go to island and do a fight, I think it should reset.
Weirdly, I right around the moment I did island is when it started... I remember I was able to... no I wasn't able to. I got 3 swimsuits, and noticed when I went to cassy's trying to figure out how to do the alissa plot.
