The number cannot be used for FaceTime and IMessage

I don't know what to do anymore. I have followed all the recommendations on Apple's website, nothing works. There are no restrictions on the part of the cellular operator. I can't activate FaceTime and amessage, as soon as I turn them on, activation fails the second I turn them on. Also in iCloud in the login and security section it shows that this number can not be used for iMessage and FaceTime, because it is not bound to the device. But the number is linked! I don't know what to do, everything worked before! Help me please!