Is your trailer filon or aluminum sided ?
If its aluminum then its an easy less expensive fix and i have no idea why its still leaking unless there are two places where its leaking and they are stopping at #1, assuming "this is it". Therefore i suspect that its filon from the action that has taken place already.
I see your roof slopes downward at the front. While this trailer is parked level, the water sheds downward over that front seam (where the roof meets the front cap). Those front seams should be lapped like a roof on a house, allowing water to shed off the roof. It should be done this way in case there is a crack in that front seam
Dicor covering.
On one of my RV's this seam was overlapped in the opposite direction thinking they had to shed water as the RV was traveling down the road into the wind. Don't ask me why, i have no idea what they were thinking.
After taking that leaky one apart to re-lap it like a house roof , I placed Eternabond tape on all my roof seams and around my vents. No more leaks.
All i can offer you is my experience with leaking filon skin:
I had recurring leaks on the right front corner of my RV and had it repaired a few times by the factory and guess what ? It still leaked. Like your mfg repair, it helped for awhile then recurred.
I would suspect that something in the OEM build process was not performed correctly and its too expensive for them to make the proper repair. Its being patched IMO.
I finally took it to an independent RV repair shop who i knew and trusted. After some lengthy conversations, the factory finally agreed to pay for it at a lower hourly rate. I got lucky, the shop accepted the terms, otherwise i would have had to make up the difference.
Once we removed the front molding,we were able to see the exposed edges of the filon sheet that was applied to the front of the RV. The edge of the filon near the clearance light had an indentation, as if the router went off its mark and made a thumb sized gouge in the filons edge.
This occurred during the original build at the factory.
Rather than strip the entire sheet of filon off and rebuild the entire front,like they should have, they tried to cover it up.
Someone (during the original build process)discovered this and thought it was a good idea to fill the gouge with some caulk then cover it back up using the molding. Less work, less expense and 'lets see if it holds beyond the warranty period' .
End result was, the factory sent a full sheet of filon to the shop. After completely stripping off the old filon, we rolled the new sheet into place and replaced the moldings. It never leaked again .
At another RV mfg., a low level disgruntled employee (prior to being fired)left out every other screw under the moldings and simply filled those empty holes with caulk then covered it using the vinyl trim strips that slip into the channels.
Eventually all those rv's leaked.
Point being, we as owners never know what the heck is going on behind the scenes . Both these mfg.'s have good customer service reputations and are praised here many times on this forum. Don't be fooled.
Take a factory rep to lunch or dinner sometime, you get to find out a lot of stuff you don't want to know about your rv .
