[JRTJH]

I think there's two possibilities:

First, you have a leak in the DICOR sealant around the top part of the skylight. The roof is "crowned" so it's very likely that the leak would be on the "upper edge" of the mounting and water would run "downhill" to the lowest part before pooling and then running inside where you see it dripping into your trailer.

Second, you may have a cracked upper skylight dome. It may well be sealed properly, not leaking at the seal, but leaking through a crack where a screw caused a split in the plastic that ran to an unprotected part of the dome.

Check it carefully, and be sure the roof, sealant and dome are clean and dry before trying to put any EternaBond tape on the area. If there's the least bit of moisture, the tape won't stick properly.

Good Luck !!!