A/C recycle/outside vent stuck open

Hi all,

First, thanks to this forum and its contributors which has provided me with LOTS of maintenance tips and saved me a good amount of money. Here is my current situation on my 2011 Prius. The vent that allows the outside air in is stuck in the open position. I have not performed any maintenance related to the A/C equipment so I am not sure what caused this or how to troubleshoot. Oddly enough there are no YouTube videos about this; at least I have not found any. So far I found that the part that moves the "flap" to open and close is underneath the radio. I removed the glove box and the black plastic cover underneath it hoping it would give me access to the "flap". I see the mechanism/level that moves when I push the "recycle/outside air" button, but of course the access is limited without removing part. I am searching for some guidance before removing any unnecessary parts/equipment. I am including a diagram I got from the dealership hoping it makes sense to someone here. I not sure if the part/mechanism that needs attention is on this diagram, but it's worth a shot. Thanks in advance and God Bless!