I am having this same issue too. I have did a network settings reset and that didnt work. After reading other posts from another site I tried the hard reset and it has only did it once so far. Hopefully this helps! But does anyone know why this is happening?
Are you texting through iMessage? or is this text messaging?
I would like to take a look at your device registration. Can you please PM me your phone number and I will take a look. Also please provide your zip code where you are having this issue.
Sprint Social Care & Support
I am only able to reply to group texts when WiFi is on. Even sending individual texts doesnt always work and I have to click the red exclaimation mark and hit "Try Again". Anyone have this issue or possible solutions to this issue????