They removed its flaw, they seem to be able to upgrade these things fairly quickly then.
Socket to 'em!
They're evolving? New models? It was the wrong eye?
I think it's because the paladin is nearby
Unlike the ones that attacked her previously, these simply attach to people to capture them. They might trade being deadly in exchange for being harder to kill.
My guess is that the paladin actually being present is keeping it alive. The same forces that brought it to life may be able to keep it that way.