Blank screen after splash screen

Hi,
A newbie here. Just having this problem. I try to publish my app but it seems that every time I run a simulation either using android studio or xcode the app will have blank screen after splash screen. However if I run using “ionic serve” or “ionic serve --lab” and “ionic cordova run android” on my device this problem did not happen.

I try to find solution but none solve this problem. Need help urgently.