Ionic Angular App on Ios

Hi, We have an app which is working on all Android Platforms. We shift it to iOS, it is working using ionic serve command and also working on ionic Cordova run browser. It is also building successfully for iOS. But when we run it on simulator, the app hangs on splash screen and not going beyond it. Help needed to load the app on Simulator, rest all is working. Looking only for very small job as it can be fixed in 30 min to 1 hour who is having an experience on it. Regards