Saggy bottoms checking in here! LOL!!!
I've been fighting a small leak somewhere on my slide. (26dbh Patriot) I've witnessed the water after a rain, dripping from the corner of the loveseat, and on the floor under the slide. The water migrates to the undercarriage insulation.
I've resealed stuff, cleaned and inspected the roof. Replaced the vent fan that I suspected due to small amount of water on the bathroom floor. It only happens when it's sitting at storage. With the slide OUT, it doesn't leak. So I cleaned up all the seals on the slide.
After our recent week long trip, its rained pretty good a couple times. I went and checked on it, and NO WATER. I'm glad, but I didn't change anything since the last time it was leaky. Super frustrating.
Long post, but the saggy bottom may be a leak from just about anywhere. Mine was/is definitely somewhere on the slide.