Okay, sorry, led you down the wrong path, there. Does not sound like an HDCP problem.
Since I’m curious about this problem, I’m going to try a few things when I get back to my own machine. I’m going to upgrade to version 3.7.3 of the software and attempt to capture from a 1080p24 source. Whether that works or not, I’ll also try to capture a 24PsF source, too, but I can’t do that one today, because I’ll have to borrow a deck.
I hope you either get in contact with Blackmagic or find a solution, but I’ll post my result here anyway. Since you’re having such a time, and since Danny Hays has never heard of progressive working with the Intensity, I’m not expecting either to work.