I ran into the Birth++ issue as well. I fixed by changing into a swimsuit at the fairy village spring as someone mentioned above, but I also found that works in the mansion's bath and in the baths in neko village.
I just tried doing the pyramid before the royal city. now I'm stuck, and I overwrote my save after entering. I can't interact with a few of the green statues or the jail cell (even tho I have the key). I guess I need to start from scratch or wait for the update if I wanna continue :(