We have a 2018 Windsport (also known as "Wind Song" due to the whistling).
Quick fix: take some 1.5" blue painter's masking tape, make a full "frame around the outer edge of the front grill and then run an "X" across the full grill. Basically you are trying to change the airflow. That will save your sanity during your upcoming trips until you do the full fix. For those that don't know - imagine a kid blowing into a 22calibur bullet shell, that is how bad the whistling was in ours at 55-60 mph.
Real fix: my dealer replaced the front grill under warranty with a different pattern in the plastic, solved it. Or like another person said, mount some screen behind it -- all to change the airflow.
Now, the really funny thing is after this fix, all is OK EXCEPT when driving in the rain, the whistle comes back! But only in active rain/wet road! Go figure!
BTW, another newby tip for Windsport is to upgrade suspension parts. SuperSteer, Rear Track bar and I just did SUMO Springs - wow what an improvement. Not cheap, but you can go at it in phases.