I have a 2013 Eagle Cap, it did the same thing, well it didn't turn my driveway white, but it did goop up the windshield for a few months, but then it went away. As mentioned, I think is is new caulking/roof material rinsing off.
I also used steel wool as mentioned in the earlier post to clean the windshield up.
Give it six months and see what happens.
2021 FORD F350 dually 4x4 with 4.30 gears
2013 Eagle Cap 950
480 Watts Solar, 3K VictronConnect Multiplus II, VictronConnect smart DC-DC charger, VictronConnect 100/30 solar controller, 250 amps of lithium batteries by LifeBlue