Unfortunately, I think you come off looking like a stalker in this one.
He said, “this isn’t going to work”, and closed the door.
At that point you should have just moved on.
Instead you seem to keep circling back to this one individual who clearly wants nothing to do with you.
Although perhaps unprofessional, you honestly don’t know his motivation for his behavior.
Nor do you need to. What you do need, is to move on.
I know endings without closure can hurt and be confusing, but do yourself a favor.....just move on.