Have. 2015 2400ws with a spongy floor area right behind the drivers seat in the corner. Have yet to find source. Can a leaky storage seal in the slide out be the cause, as not sure how water could travel from the compartment to the floor since it is in the slide out metal box. Any suggestions would be appreciated. Still doing water tests with hoseÖ
If the seals are not dry and brittle or cracking, I would think that they don't need replacing. One thing that I do is place blocking (not much) to tilt the Rv so water runs away from the slide opening.
I do treat my seals with spray silicone when I wash and wax.