In some cases this is admirable.

Guy in group message who doesn't say anything. He doesnt ask you any questions about you and doesnt seem interested in who you are. Just try to show that you like him without bending over backwards or selling yourself out. One theory is that he needs to have a deeper intake of breath when he sees you because you get him going so to speak and he can get a deeper breath with his mouth open.

Your messages content may also clue you in to why there was no respond. If they are not responding to the group chats then you could also send him a message and say you will remove them so that the notifications are not bothering them. Some people are very private.

He never congratulates you on anything. There are multiple reasons that this could have happened to them but commitment-phobes hardly ever know what they want. If you like him I would say reach out to him a bit but dont pressure him to commit or talk about his feelings toward you at this point.

The fact that this guy uses his phone a lot around you honestly proves that he doesnt feel the same way. He might just like the digital company. He Doesnt Know What to Say.

But His Texts And Calls Have Stopped. He treats you like everyone else. If you ask a different easier question then he might actually respond.

He doesnt seem to know who you are. This happens quite often when it comes to guys who text you but dont seem to actually have anything substantial to say to you at all. Approach each one of them individually and ask them if they feel uncomfortable being in a group chat.