I don't think he is playing games. He is just different than you in this. It is possible that he doesn't really get why it is such a big deal to you.

This may be something you have to adjust to; because making it a "have to" on his 'to-do' list isn't really gonna achieve what you hoped for, that he is thinking of you and texting you to prove it.

If you must, explain to him again that this small thing means more to you perhaps than it does to him, but it would make your day to get a little cheerful hello. All you can do is ask, communication is key here.

All the best to you.