Other than the obligatory roof check (looking at seals and caulking), perhaps something (tree twig or a stick) made its way into the slide gasket and water may be entering that way.
While on the roof, you'll be able to confirm that the canvass slide topper retracted correctly. Stuff like that.
Robi & Dale ---- Go Navy ----
2016 Winnie TOUR 42'
Tow: '08 Buick Lucerne