How come my databinding is writing out the Length property?

Question

So I\'ve setup a viewmodel to where it binds an ObservableCollection to my DataGrid.

It prints out the value just fine but it also prints out

Answer 1

I forgot to add the property AutoGenerateColumns="False". Not sure why it was set to true by default or why it woudl choose the length property of all the properties but I guess I got it fixed.