Why can't I receive group text from a particular person in a group text

[AC Question]

I am in a group text with several of my friends but whenever one of my friends replies to the group text I receive and individual text from him saying the message from Person not downloaded. If I try to download the messages I get a loading sign for a second and then nothing happens. Other people are able to receive messages from him in the group chat just fine, and if he sends a message just to me there isn't an issue. I have Moto X and he has a Galaxy 6S. I have checked and I know I have MMS turned on. It is just this one person that I have an issue with group text. Anyone else have this problem?

Thanks.