Major water leak, slide slide, with slide in on 2015 Windsport

[LVD]

Hello all, hoping for advice where to look for major leak in heavy rain. Slide was in, pouring rain. Water poured in (used cups to collect) from wall under microwave and under microwave. A bit later, water was on the floor across the length of the slide in sections. Roof or slide seal issue?Any thoughts greatly appreciated for where to begin to look. 2015 Windsport. Many thanks. Laura

[abjbrtd]

This YouTube would be a good place to start.
Sometimes when our slide is out a long time the secondary seal will start sliding out, the one on top has almost come all the way out before I see it
Sounds like yours is gone or in very bad shape.
I recently replaced most of ours with this.

https://www.amazon.com/gp/product/B08F69QN73/ref=ppx_yo_dt_b_asin_title_o02_s00?ie=UTF8&psc=1