My iPhone won't send SMS over WiFi to a group after switching from eSIM to SIM

As the title states, my phone 13 Pro was switched from Verizon (e sim) to Cox (physical sim). At first, we were confused that my phone didn't have a sim, but we found out Verizon uses an esim. When we installed the sim card, the cox became a "travel" sim card, with my old service still as the "primary." I was able to remove the "primary" and enable cox only. This resolved the first issue which is probably tied to the rest.

I found the phone was no longer sending MMS messages, only SMS. If I started a text, it would be blue to indicate MMS, but would turn green a second later. Turns out under Settings > Messages > Send and Receive, the "start new conversations" was unchecked for my number, checking that solved the MMS issue.

I also found wifi calling was off and was able to enable it, and have tested it.

I have not been able to figure this one out, I am on a text chain with 6 other people, some have iphones, some do not. I am in a spot with poor reception, before, I could enable airplane mode and send messages via wifi calling, now I cannot, it instantly says "message not sent." "Send as SMS" is enabled. I cannot find another setting to get this to work again. I can send sms to a single person, but not the group. It does say "cox mobile wifi" in the corner.

Anything else I should check?

[Re-Titled by Moderator]