Okay, I just tested it. The struct does matter! I can use an actor pointer and it works fine. I can use an array of actor pointers and it works fine. BUT! If I use an array of structs of actor pointers, then it crashes! I attached what may be a more accurate call stack. (Unless I’m going crazy.)
Anyhow, this has everything to do with the way the data is structured. Unreal just doesn’t like it.