Why do my messages display as not delivered

Hey there Lumbersnax,

Upon researching your question, we were able to find a link that discusses your issue with sending messages, along with the next steps to take for resolving this: If you can't send or receive messages on your iPhone or iPad Please keep in mind that this would include contacting your carrier to make sure everything is ok from their end.

If you’ve already tried all of those steps, then the next step would be to let Apple Support know what's been tried as they'll be in the best position to assist further: Get Support

Cheers!