Read Receipts Not Working

Hello,

My boyfriend is having this issue with his iPhone 6. His iMessage read receipts are not working. We have the read receipts turned on and also made sure they're on in for each contact individually; however, when he sends me an iMessage, they now only say delivered as though he has them turned off. I can see it right now on his phone - the settings are all turned on. What is going on with this...?

Help would be much appreciated!

thank you guys!

LJ