Unable to use hotspot on iPhone 15 Pro Max after iOS 18 update

After the recent software update IOS 18 in my iPhone 15Promax, I am unable to use hotspot, it says contact your carrier where as the carrier says this issue is about your phone's software update, how to fix it

I tried to restart,

I tried to reset my network settings both didn't worked.

[Re-Titled by Moderator]