My phone is showing an error that text messages are failing to send when they are not.

[Kevbev22]

Every time I send a text message, the recipient successfully receives the message and is able to reply, however the phone shows an error that the message did not send. I have tried everything, restarts software updates Airplane Mode nothing is fixing the issue. Using iPhone 12. 

[pgn]

This is a long one, but worth checking out, @Kevbev22 - see if any of the advice in here helps - yes I know your msg is delivered, but read on down a ways:

https://www.makeuseof.com/tag/fix-imessage-not-delivered/