Soft spot in floor

Thanks for the advice. I can take pictures but the flooring is still down. I can just feel the soft spot. I know water has to be coming in from somewhere. I looked at seals on roof and everything looks good. Id rather not have to pay for a pressurized leak test but I've done a leak test with the water hose and can't find it. I just know if I pull the walls I'll see exactly where its been coming in. We last used the camper about 4 months ago and that spot wasn't there so its been leaking pretty good for it to have done that. Also I'm worried about mold. So it may be better to pull the walls.