For anyone wondering, I ended up going to the dealer and had to pay $700 for a new recirc door and actuator.
Seems to be a common failure mode (that’s what mine was as well as I commented earlier). The star spline on the recirc door doesn’t have enough meat around it and it eventually just shatters to pieces.
It’s a complete bitch of a job to replace so I’m surprised you got out of it for only $700. I did the job myself and the recirc door was $150. Technically the dash has to come out but you can make room if you bend the metal bracket holding the HVAC plenum at the front (under the glovebox).