I have a 2018 Era with probably the same vinyl flooring and haven't experienced a soft floor. It sure sounds like a leak. I forgot to open the shower control when I winterized a couple of years ago and it ruined a valve seal causing a leak inside the wall that was not at all obvious. I found it early on because we always use our internal water pump and never connect to city water except to fill the tank. The leak was causing the pump to cycle when the faucets were off which got me looking for a leak and replacing the valve.