Facetime failed with Iphone 7 Plus with IOS 15.2.1

Hello

I have seen the same issue with other users but running older IOS, I have the same problem with IOS15.2.1 here what I have done so far

Facetime failed once I click on accept or dial out Facetime audio or video calls

Here is the steps that I have tried

1) iphone 7 plus with Latest IOS 15.2.1 - All Apps are up to date

2) I reset my network connection

3) Log off and log on to Faetime

4) No Screen time been activate

5) Reboot my iphone

I follow the steps in the this link If you can't make a FaceTime call on your iPhone, iPad, or iPod touch - Apple Support ( But No luck)

What else can the communities sudgest rather calling support that could charge X$ for an old phone

Thank you