Just remember that the well Walker is an opposite switch i.e. always on and when you hit it it triggers it off. I’ve seen the connector for it go bad and cause switch hits because of this so worth unplugging it and making sure it’s all nice as breaks in the circuit cause a false positive - the cable runs to the left side of the under playfield.
Issue was still there after I checked the micro switch, like I said it wasn't bent and seemed fine. I don't know if this is a coincidence but the right slingshot rubber went and after replacing it no problems at all. Could the sling somehow have been responsible for registering hits as the rubber was obviously on it's way out?