Hello,
When reading all elements from category windows, dynamo reads also other categories (see example (columns?)? Anyone knows why? Window has no link with columns!
thx
Alexander
You could try with Element.Name instead of FamilyType.Name which obviously requires a family type as an input 
thx,
answer wasn’t exactly what I expected, but it helped and solved the problem .
I would have to see the actual files to know, but it looks like you have family types which have the same name so it’s grabbing the first of the two families based on the name.