Thanks! Any thoughts as to why? I guess the content array was getting lost on each refresh?

I think since I named it "uuid" there would be nothing linking the expected "id" to it

OK, wasn't having to do with my uuid attribute. Passing id:.self fixes it but still curious why the SampleTrip didn't do it. I was leaning towards using a PlayerEntity? because the "let player = players.first(where: {$0.id == id})" part seemed less efficient.

Thanks. How does the SampleTrip sample get away with not using id: .self? Is it possible that I've confused something additionally because my model for PlayerEntity includes an explicit uuid attribute in addition to any that are auto defined by CoreData (I can check this)