Hello,
I am using Revit 2019 + Dynamo 2.0.3
I encountered a strange problem - List.AllIndicesOf returns empty list with data that was passed from excel.
I first get some booleans so I do not see why it fails.
Has anyone encountered similar problem?
Your pointing the Node at the wrong Level of your list. The list has sublists, it is asking if those sublists are True. Off course they are not. Set it to @L2 and it should work. Read up on lists and levels in the primer.
You are right 
I am still a bit lost with how lists are managed dynamo vs grasshopper.
Thanks again, have a good one!