We had that issues on the dinette slide on our 3121 Forester, which was the above floor LCI. Leaked when it was in and out in the same location you mention. Sometimes on the aft end depending on the rain and which way the coach was sitting. Took it to factory, they completely redid the seals and added a better wiper seal on top. They rain tested it in their booth, and said all was good. Got it home, still puddles of water. I can only speculate how it was getting in, but take a look underneath the slide. Follow the end wall wipers down to that point. If water runs down the wiper and makes it underneath the slide, on ours, there was little to keep it from going on inside on the floor. Kind of hard to explain a fix as I don't have the thing to take pictures of what I intended to do. We never did fix it and sold it with the issue. The rear schwintek slide never did leak that I know of.
John and Rebecca Dickson
Emma-7 / Little John-5 / Iva-1
Full Timing Again, Rev B
2013 Ford F-350 Lariat CC LB PSD
2015 SOB TT - With OC's Awning Poles (#8)
At least in Heaven, RVs will be perfect, and I won't have to keep fixing them.