Porting old number error

I have ported my original number but rcs message are displaying the number of sim provided ?

ChrisD7 When RCS chats show an old number (often after porting a number or changing your SIM), it happens because the Google servers are still tied to the previous SIM data. You should Unregister via Google: Go to the official Google Messages Chat Deactivation portal. Enter your current phone number and verify it with the SMS code to wipe the old number from the RCS servers.