Just stating the facts/information that we know---from the OP
With all due respect---if the following occurs...
<<<LG dryer DLEX7177RM, customer complains that for about three months, the unit has been leaven clothes damp.>>>
<<<Even in the manual settings.>>>
Then that translates to---the dryer runs **at least** for a period of time **longer than** five minutes.
The clothing is not *very* wet at the end of the cycle---but "damp".
During *any* Sensor Dry cycle---a disconnected MOISTURE SENSOR PLUG---would cause the dryer cycle to end in five minutes or less.