INTJ avoidance in social settings?

Hey INFP here!
I tend to get along with INTJs fairly well. The INTJ women seem to naturally gravitate towards me. As an infp girl I find them really easy to talk to! However, I’ve noticed a behavior of avoidance in an INTJ man towards me. I recently began attending a church Bible study group. He’s in it. However, he used to go to the same school and church as me… we were never close. But we were always amicable. I’ve noticed in the beginning he was very reserved towards me. I initiated all the convos and he would avoid eye contact and gave short responses . (Fast forward to the 4th meeting). He lightly attempts to include me in the group through brief commentary on my comments and laughs at my jokes. BUT he also avoids all physical proximity. I sat next to him cause it was the closest seat open and he stood up immediately and started looking at things in the room (wandering while doing nothing). The avoidance was so obvious that the ENFJ had to swoop in and take his seat to bridge the awkwardness. I’ve been friendly and initiating most convos with him… not often but enough to show warmth. I would just like an explanation to this behavior from other INTJs. Are INTJ men generally just slower to warm up to people?

I just really want to be friends with everyone in the group and have it still feel like a safe space for everyone. Let me know if I’m crossing boundaries too fast or if maybe he doesn’t desire a friendship! What’s making him that uncomfortable?