It sounds as though you are having a problem in the heater box assembly.
There are countless service bulletins about air doors breaking and blend air door motors failing.
Since the problem has occurred all at once, on both sides, I am leaning towards a broken air door.
I can tell you that the last heater box that I removed I ended up replacing two air doors and both the passenger's and driver's blend air door motors.
I order to resolve your problem it sounds as though the heater box will need to be removed and all of the doors examined.
Even if only one door is found broken, have the passenger's side blend air door motor replaced.
The passenger's door motor is a very common failure and the entire box must be removed to replace it. Rather than having to pay the labor twice, have them replace the motor..
You can expect that this will tie your Jeep up for about 2 days. 1/2 day to pull it apart and another 1 1/2 days to wait for the needed parts and reassemble everything.
Please ask me any questions that you may have,....Thanks, Josh