Is he not interested?

2 years ago I met a guy, let’s call him Z. Anyways we talked for a couple months and then I moved to another state and we went about 18 months without talking. He texted me out of the blue in Sept 2019 to catch up with me and it was nice to hear from him, but yet again after a couple days we quit texting. About a week ago I kept thinking about him and dreaming about him randomly so I took that as a sign maybe I should check on him, he was going through a tough time in Sept selling his home and moving and mentioned therapy. So I figured I should check on him. Well we texted two days in a row and caught up again and then a few days go by and no text and then he randomly texted me yesterday and was super short. He just sent a hey. So I said hey what’s up. He said not much. I asked if he was okay and he said yeah. That’s it. I felt he was being unusually short so I just reassured him that he didn’t have to feel obligated to text me, but I was always here if he wanted to. I told him the other day I texted just to check on him and catch up. Well he replies with I enjoy talking to you and I don’t wanna bother you. I told him he would never bother me and if he wants to text then text me I won’t take offense either way and he reassured me again he enjoys talking to me. I ended up just reading it and not replying because idk what to say to that and I had already said my part. Idk why he would just text me out of the blue on his own like he wanted to start a convo but yet he was being short. I feel bad for leaving him on read but I didn’t wanna keep forcing a convo. What do I do in this situation? We’re good friends, and I want us to stay that way.