FaceTime and call issues on iPhone 16 Pro Max after iOS 18.3.1 update

After updating my iPhone 16 pro max to 18.3.1, FaceTime calls drop and make it unable to call back. You click on the person's name in the FaceTime app and it does nothing. After about a minute, the phone will do a hard reboot and everything works again for a little. On calls, if I have the phone on speaker, the phone will randomly turn off the speaker. On FaceTime and calls, if I have the phone on mute, it will randomly turn off the mute. Cellular connection has also been horrible. Using WiFi, it's not as bad.

I’ve tried updating the phone on my Mac to see if it’s just a bad download, did not fix the issue. Tried restoring the phone, did not fix it either.

Been in contact with Apple support and been told it’s most likely a buggy update and I should just wait for the next update to come in.

[Re-Titled by Moderator]