E Z Peaces wrote:

If the machine is the same, three factors besides moisture can
cause clogging:
The amount of grass you are cutting.
The stickiness of the stuff you're cutting.
The amount of air the mower is sucking.

(cutting up-hill vs downhill, having a clean bag that allows airflow)

Bend the bag support frame so the back end of the bag is flat or
slightly lower with respect to the chute opening.

Problem solved.