PostInitProperties functions is called multiple times

Hi, I’m developing iOS app with UE 4.27.

I have MobileInstance class inherited from GameInstance class.

it is overridden some functions. PostInitProperties function is one of them.

Strangely enough, InitProperties is always called three times after overriding that function.

it is always reproduce on mobile device like iPhone or any android mobile.

I feel like missed some important things.

why PostInitProperties function be called multiple times?

please somebody help me ~