A lot of RVers will seal the top of the roof, but they forget that the seam of the front cap continues around to the side, and sometimes the leak will be on the curve part where the side wall, front cap and the roof meet.
Leaks are hard to find. I have read where you can also apply air pressure on the inside and apply some kind of foam on the outside to see where it will bubble up to find where water has been seeping in.
I do not know what coach you have, but if there is a window or even the door gasket that is bad, water could get past the gasket and work its way into the inside wall of the coach. That is when you have to pull the gasket back on top and apply windshield sealant. All you need to do is the top of the window or door gasket.
2002 Gulf Stream Scenic Cruiser
330 HP Caterpillar 3126-E
3000 Allison Transmission
Neway Freightliner chassis
2017 Buick Envision