Hello tushartosi,
Welcome to Apple Support Communities!
If we understand your post correctly, after updating your iPhone to iOS 15.2 Wi-Fi calling is no longer working. We'd like to help!
If you can't turn on or use Wi-Fi Calling, make sure that your carrier offers Wi-Fi Calling and that your devices have the latest software. Then, follow these steps if you can't turn on Wi-Fi Calling or make a Wi-Fi call. Wait two minutes before you go from one step to the next.
- Go to Settings > Phone > Wi-Fi Calling and make sure that Wi-Fi Calling is on.
- Restart your iPhone.
- Connect to a different Wi-Fi network. Not all Wi-Fi networks work with Wi-Fi Calling.
- Turn Wi-Fi Calling off and then on again.
- Go to Settings > General > Transfer or Reset iPhone > Reset, and tap Reset Network Settings."
For more information about Wi-Fi calling, take a look at this article: Make a call with Wi-Fi Calling
Let us know if you have any questions.
Thank you for using Apple Support Communities.
Take care!