FaceTime audio not working

I by an iphone 11 pro max from Shanghai China Apple Store and when I came back to my country after a while of using it I realized it has no way to make a FaceTime audio

And after some researchers about this problem I find that many other people have the same problem and the limitation is from China and its on the phone IMEI code

so if a phone have a china IMEI code it won’t let you use FaceTime audio

so this makes a very big problems for those who buy their phone from China and get back to the country

and the only way to solve this problem is to change your IMEI code which thats illegal

this type of limitation is really inept and disappointment ☹️

my question is why don’t you make the limitation just for the Rogaine or location of China and release a new update That let iPhone users in other countries to use FaceTime audio call according to they location ???

I will be very happy if I get some convincing answer tnx 🙌🏻🙌🏻🙌🏻