well from the pure physics point of veiw
you have very hot moist air which should flow through condensor front to back
you should have room air blown left to right through condensor.
if that does not condense then physics is wrong
so either the condensor is blocked. customers clean front to back but forget left to right
or
door filter is blocked, again customers clean it but dont wash it every now and then. get lots of those blocked
lastly had heaters blocked before today
Dave