Does anyone know what makes a ship (inside an area beacon's range, set to deconstruct) a valid block for deconstruction?

Seems like the nanites go after all unclaimed blocks, maybe blocks owned by other players, and ships not actively producing power.

I have an area where I leave cargo containers with ore to be auto deconstructed/collected, but the ships that deposite the containers need to be reliably safe. Since they're solar powered, it seems like my nanites attack the ships if the docking area is currently in the shade.
These docking ships are owned by me, and have batteries.
The ships seem to be ignored by the nanites if their solar panels are producing power.