(SOLVED)
I dug into this more and discovered that somehow I managed to import the meshes with no material slots ie: no “Elements”. I have been working with UE professionally since 2.5 and I didn’t even know this was possible. At any rate since they were being used as HISMCs and getting assigned a material in Blueprint they would for some reason draw but the engine thought they had no “elements” so they wouldn’t cast shadows I assume because there’s a flag inside each Element for cast shadow that was probably null. Anyways that appears to be at the root of all my issues. I still need to figure out why the meshes were importing like that but I assume user error. Sorry for the confusion.