Soft spot help

speaking from experience since im now repairing water damage i would sa that you need to first check the roof, windows, access doors, marker lights, screws and trim etc first. water may just be dripping ever so slowly and not noticable.. at first i thought my water damage was limited to my floor and i have since replaced a 5 foot x 8 foot section of my subfloor, insulation etc and about 3 feet of a wall. the water was coming into the wall from behind and ipper awning bracket, tail light and window. your best bet is to gain access under the camper to possibly assess the damage before you start removing flooring etc... honestly though if you have a 4 foot section of soft floor i would replace that section as soon as you can before it ruins a much larger section of floor. i would also check the walls. it can create alot more work and you might as well add new flooring to your TT so its not mis matched but its gives you an opportunity to personalize your camper.

good luck, i feel your pain