Wierd Behavior of Ballphin Palaces

Sometimes, ballphin palaces DON'T SPAWN ballphins at all even with resident ballphins ALIVE and ENTERED LAST DUSK. I've already built several palaces near my fish farms and coral reef field, but on random occasions, NO ONE leaves these palaces, leaving my fish farms unprotected from crockdogs. (I'm quite confirmed that the resident ballphins are alive.)

Besides, I also notice that even all resident ballphins are alive, they return to only a SMALL part of the palaces at dusk, thus only a FEW of the palaces' lights are on at dusk/night. (e.g. I've built 18 in total, but usually only 3-4 lights are on at dusk/night. Besides, if the bug discribed in the 1st paragraph is triggered, no light will be on instead.) According to wikia, a palace can hold INFINITY ballphins, and I guess this is the issue. I don't know if this is intended. If not, please fix it.