Given the rate of the drip....which is very slow....
1) back off the locknut (loosen) and start to re-tighten. We're not looking for major torque that could crack the housing....but find the SWEETSPOT of tightness where the leak/drip stops.
2) sometimes no matter what you do... that plastic part has enough of a defect in it where it will always slowly drip. If you put some light air flow around it, SALTCREEP will eventually seal it up. Sounds crazy but thick saltcreep can be a tough as glue sometimes. Trick is to have light airflow, just enough to keep drying out that drip and it will encrusted over itself. While drying out the drip have a small container collecting the drips.
HTH
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