Sometimes I see a red film on top of my curry. It’s like a grainy layer of film. I don’t think it’s fat because the curry is too hot to solidify by this time. I’m wondering if it’s powder clogging together? In any case I do think the curry hadbrbb cooked properly. What is this film?
This really sounds like a layer of fat/oil floating on top, with some "graininess" from spices or other particles floating in it. The curry being hot is if anything part of why this happens: oil/melted fat floats on water.
As noted in the comments, the description could be clearer, and so it's possible this is incorrect, but that's a very common thing to see on top of curries, and rich stews in general.