It's not and it wasn't when it was working.
Player tree is:
I changed the root Arrow node from an Area2D to a Node2D and made the Area2D part of its tree. Seemed to do the job.
Not sure why it was working on my first attempt and not here, though.
Reason I redid it: I had placed my main tscn in the autoloader and got hit with that double _ready() bug.
I guess I'm set now. But thianks!