Just had a 4runner at my dealership i was working on on monday with the same issue. It was as simple as the rear window not being all the way up. Roll the window all the way down and then all the way back up. Good chance that is the issue.
Amazing! Did what you said. Window down and up again. It worked this way. Thanks so much.
SO the reason was the window was not all the way up and therefore did block the wiper and defrost?