One of two issues to check:
1. The factory sometimes misses installing block off's and drip diverts or installs them incorrectly.
Check these area's first. See attachment for locations to check.
In particular, this purple panel in the document CAN be mounted on the outside of the L bracket instead of inside per design. This will allow water to leak outside the cabinet.
2. Check RPM/ static issues.
Coil Face velocity could be an issue in which you would reduce the airflow to solve the water carry over issues.
SEE video of field test showing leak locations on the insulation.
Lower airflow and question the actual static pressure verses design static.
Also outside air could contribute to the issue as well as short cycling due to oversizing the unit.