I'm sure that u are creating a new node with Node(pos), a node with default values like passable = True, to access to a node in the grid just pos.position or pos.passable.

I confirm. Even accepted solutions are too slow.

It seems most solutions pass in about 500 ms, a recursive solution passes in about 2 s.

Try looking into the difference between '==' and '===' operators
https://developer.mozilla.org/en-us/docs/Web/JavaScript/Reference/Operators/Strict_equality