I have Iqoo Z6 Lite. The IQOO's Phone app keeps freezing after tapping on it. I've also tried opening 'Google Contacts' at the same time and I was shocked to see that both the apps were behaving in the same manner.

By Freezing I meant the screen goes black and I have to clear apps from recent to get it working.
I've already tried clearing cache and all the methods but it's still same.

It's literally annoying and frustrating in emergency situations.