FaceTime failed after IOS upgrade

I am running 14.7 IOS version on my iPad 8 and I have been experiencing FaceTime and phone calls issues

recently. Before the last update it was working fine, my internet is fine, my iPad is brand new, the only problem I see is the new update. Every time Apple comes out with a new iOS version there is always a problem and it is very annoying. Anybody that can help me to resolve it. Making or receiving FaceTime and phone calls crashed as FaceTime call failed. I used to communicate with my grand babies every night and now is so frustrating that my calls don’t go through my new iPad.