[JRTJH]

^^^ What they said: If you don't already have water intrusion under the front cap molding, you will have after washing your RV and pulling it through one rainstorm.

NOW (not later) is the most advantageous time to clean the old sealant, remove any that's damaged and apply a fresh coat of self-leveling DICOR to all the areas that look like the photo that are on your roof.

Trust me when I say that area is NOT the only one allowing water under the sealant. The UV damage from the sun in SoCal will destroy the DICOR in short order. Your trailer is a 2016, so it's potentially been exposed to 4 years of UV deterioration on the DICOR sealant. Even with a "modest 3 years of deterioration" you're at least 2.5 years behind the power curve on roof maintenance.....