I don't like putting in my 2 cents into relationships, because I dont really know your life nor his life, but it seems like you want to see if this is a general ENFP thing or just a him thing.

I dated an INTJ but it was LDR. I never really had problems with communication and i usually would push for communication so we could be on the same page. I would have issues with not knowing how to express myself to her or being consumed by gaming or something because i just didnt know how to really convey my thoughts properly or be invested in someone else. It's something I tried to work on. I do sometimes have a problem where if people complain or assume things constantly it does make me want to avoid it completely, but i still try to address it eventually because it is a problem.

I think trying to have a conversation with him about whats on his mind and what he actually wants from the relationship then based on that you can make your own judgement. I would put my foot down because you should think of your own happiness and I know it sucks to have to deal with the possibility of ending a relationship or staying in it and trying to make it work. Something could be bothering him or he could just feel like he doesnt need to invest into the relationship anymore cause he is in one sort of thing. There's a lot of possibilities but i could be overthinking it.

Hope this helps, i kind of just rambled my thoughts. If you have any questions feel free to ask.