I am not saying this is your issue, and Broncos are known to have weak air flow underneath this seats. But others have found that the air ducts have not been correctly assembled from the factory in various places.
So if you're truly not getting air flow out of the passenger side (making sure your dual zone isn't simy the issue), then there is a chance that you're simply disconnected.
Maybe read your hand up under and feel along to see if all that error is coming out somewhere it should not be.
I am assuming if that is the case they'd have to open the dashboard to reconnect - not fond of that idea. Had an appointment today, but cancelled - gonna look around some more at settings, etc.
Obvious and probably not your issue but there are flow adjustments at the bottom of the vents. My wife has a tendency to close them off most of the way. Then the kids get in and are like I’m not getting any air. Make sure those are open.
I had an air vent on mine that was stuck closed and the adjuster wasn't connected/ broke. I pushed it open with a screw driver, but dealer still had to replace the whole vent. And yes the dash had to come off, and yes they broke the trim on the switch panel. But the dealer made it right and gave us a loaner for the week they had it.