I don't remember modifying anything on my phone.
I tried some other RPG Maker games, mostly adult games, and some were MV and most were MZ.
I got the same visual bug on JoiPlay. It was a lot slower, going to almost 8 fps on the initial city, compared to the "usual" 12-16 fps.
I really think my phone is just that bad. It's a Samsung Galaxy A21s. Should've said that earlier.