How do you have a conversation with someone who always turns things into an argument?

My boyfriend and I have been together for a year now and since day one I told him it’s not us against each other but rather us against the problem. I told him he can always talk with me if something is on his mind, it doesn’t have to turn into a fight. We can figure anything out together, I expect the same from him.

Every time he asks me what’s wrong or I come to him with something that’s on my mind that is bothering me, he tells me he’s not doing this right now and that he doesn’t want to get into an argument. After he says that I get put off and I always say I’m not trying to start an argument ever I just want to talk to you about it so we can come up with a solution. It’s all downhill from there because I feel like my feelings, wants and needs are brushed aside because he “doesn’t want to argue” when that has never been case. How do I explain to him that it’s never an argument but rather a discussion??? 🤷🏼‍♀️