2005 Prius thumping behind dash related to air recirculation

Hello, new here. I’ve driven my Prius a lot since I got it and never had any issues. Now I’ve just noticed all of the sudden it’s thumping pretty loudly. It sounds like it’s coming from the middle to passenger side of the vehicle behind the dashboard. I can’t hear this noise when I am outside with the hood open and the vehicle on. Only from inside the cabin. It’s not constant, it will do it randomly and for random amounts of time. But I’ve noticed it will only randomly make this noise if the air recirculating is active. When I press the button to draw outside air, the noise goes away. The noise also goes away instantly if I power off the Prius. It also does not matter if the gas engine is running or not. I did try searching a bunch on the threads here but couldn’t find a similar noise, or the videos were no longer working for me to hear.

I’ve attached a short video. It sounds louder than it is in this video admittedly. However it is concerning me, so any help is appreciated.