happens all the time
condensation on the windows with defroster on on 2005 Jeep Grand Cherokee
that could be a cracked heater core.look to see if the carpet on the passengers side is getting wet.
I had this problem with my 97 Grand Cherokee turns out it was a clogged AC evaporator hose causing water to spill over into passenger side. Moisture causes condensation on the windows. Simple fix unclog hose located lower firewall