Kitchenaid frig vent---how/where would it plug?

Most of the way thru troubleshooting a cool freezer/warm fridge issue Kitchen aid KSRS25IKBL) Appears the damper control sliding gate was cracked and hung up. New damper control on the way. But…

Advice on the site says to also check the return vent for plugs/freezing/obstructions. Non apparent from the fridge side when I remove the cover plate. However, if I do the “plugged return vent test” i.e notice the amount of air coming thru the damper (now fully open as I removed the gate) it increases noticeable when I open the freezer door.

So where does the vent return to on the freezer side? There are clearly no obstruction on the fridge side, but you can only see so far into the duct.

Thks

Air enters the top and exits the bottom of FF side on SXS. Look for louvers probably hidden by a drawer on bottom of divider wall.