Leaking at the first rain

I have this products on my 2-man tent applied what is now but no longer seemed quite tight after a few years. The first is not very heavy rain in Iceland, however, both the floor (originally 10000mm water column) and the rainfly (7000mm water column) were leaking. The amount was enough to spray the entire tent area 2-3 times, until dry, then wet (after I had these remarks but then spotted on the package).

The care product is based on water-based. The question to me is how a water-based should not be simply washed off with prolonged rain.

I can not recommend the product, unfortunately. Only the handling is very good.