Yes i have that issue again whoops you balance is low ,out of data, to send pics through text mmg. I did add 30$ to my plan that fixed it temporarily ,i thought it was payment issue but no,i still have that issue again . it seems that boost mobile and sprint merge still have issues .please update are accounts to solve this boost mobile.
I have different problem. In sudden, I can't send message to my daughter. I am able to send another messages, even to Boost network and my daughter can send message to me. The only idea of mine would be, if there is any limit in the Android messaging app or limit by Boost for the total size of the one person chat. My record of messages with my dayghter is extensive over the years, with many pictures - MMs's. My phone is Galaxy Note 9, memory half empty.
It's absolutely weird problem. Messages form other people is my daughter receiving OK.