HOT humid air inside RV gets pulled in thru 'return air' and flows across Evap Coil. Heat from air is absorbed by evap coil BUT the condensation runs down into a drip pan under the evap coil and then drains off.
Your's uses a drain tube down to ground under rig.
Trailers let it run off the roof......
The more humid the air the more condensation that will flow
ALL Normal......just keep drain tube clear.
Otherwise that drip pan fills/overflows and that condensation comes INSIDE thru return air OR gets sucked up by fan and then gets into discharge side -----drips out or blows into ducts