We had that happen to us one time. 2016 Outlaw 29J.
During our trip, the hydraulic levelers went into a fit, I got the jacks retracted, but had one more week of camping to go at another campground without the leveling system working. The site was fairly level so we did not worry much. Then a hard cross wind rain came for a day and water entered somewhere and ran across the floor some.
Not sure where water got in. It was not dripping from ceiling, nor running down the wall, just across the floor from between stove countertop and sofa. I figured that there must have been a little lean on the rig, plus the intensity of rain & wind direction. Levelers got fixed to work again, never had the water enter again, so I gave up looking.
Maybe you are not quite level enough. And/or the rain particulars were specific enough for the water to migrate in. I'm not sure.