iOS 18 SMS text issues on iPhone

Since updating my iPhone to ios18 I can’t receive any SMS texts including verification codes. I can’t text android users or get texts from them. I can’t get any group texts at all even from iPhone users if an android user is also in the group chat. I spent 2.5 hours on phone with Apple and went to Verizon and neither can help me but I know this is a glitch or bug with the update and others have complained about this. Anyone know how to resolve this issue?

[Re-Titled by Moderator]