Only one of my mesmers headgear will take insignia

I cant remember where I purchased them, but I know they were all from the same armor crafter on the same day. So why is it that only one (the one I was wearing when the insignia update came through) able to take insignia ?

Edit: I just noticed that the +energy on the non-inscribable ones has also vanished.

max armor from collectors cannot be inscripted - seems thats what u got there.

Except that all 4 pieces here are crafter pieces, not collector.