How to resolve 'Unavailable for iMessage and FaceTime' after changing phone number on iPhone 11 Pro?

Hello community,

I changed my phone number in my iCloud account using my MacBook. I received the verification code and successfully verified it, but FaceTime stopped working afterward.

I tried the following steps:

• Turned off and back on both Messages and FaceTime, as well as the "Allow Calls on Other Devices" setting — didn’t work.
• I still only see my email in the FaceTime "reachable at" list, not my phone number like before.
• Reset my network settings — I regret this step because it didn't help at all.
• Removed and reinserted the SIM card.
• Removed the number from my account and added it again using my iPhone.
• Restarted the iPhone after every step — still no success.

I also signed out of FaceTime on my MacBook and signed in again. I got a notification saying the device was added to FaceTime, but I'm still facing the same issue.

In my Apple ID > Sign-In & Security settings, it still shows “Unavailable for iMessage and FaceTime” under my phone number.

Device: iPhone 11 Pro

iOS: 18.4.1

Has anyone else faced this issue? Is there a solution?

[Re-Titled by Moderator]