Chomp does not indicate that it has failed to send. It has no issue sending or receiving MMS messages, and it successfully receives them.

It fails to send SMS text messages even after chomp's cache is cleared.

If I change to the Google Messages app it does indicate the message as having failed and offers a resend option, if I use that the SMS does get sent proving this is a CHOMP ONLY bug of some type (2 actually, the failure to send and the failure to detect the problem).