Been working with senior support quite a bit. (Thank you Tim for all the hard work and troubleshooting with me)
Apple is doing their best to work on it.
Still having missed texts.
While this problem is with multiple carriers verizon has something called the message + app so I was able to validate if I was missing texts in the iphone message app. Of course if someone sends me an iMessage it would go to the iphone message app and I kept having to switch between the apps. I felt if I turned off imessage completely and used only the version app I might miss texts as well because people are trying to send imessage. (Ultimately not sure on that part).
Things I tried that I proved with screenshots did not work and have sent/discussed with support:
upgraded to version 14.2(18B92)
Turned off wifi calling
Turned off mms off and on
reboot of phone
turn off imessage
Turned off wifi completely
turn icloud message backup off and on
turned group mms off and on
None of the above fixed my issue. Even turning off wifi-calling did not fix.
I have proven each one still had missing texts. I went from an iphone 10 with no issues on version 14.1 to iphone 12 pro on 14.1 Upgraded to 14.2 and still all these issues. Have tested all of the above on version 14.2 as well.