I eventually had to render it in LW (I know, bummer, right
) But I was reminded of a setting I've changed that may help.
It's the "Parallel Samples" and "Max Tile Samples" settings in the Kernel. I'm able to up the settings on the projects that are working, and am wondering if they're strained on the TFD project (I'm only doing one at the moment, but it's a template for the other 5 shots I have)
I don't have time to test it right now, but will check it out and see if that's the issue.