I removed the vent and I can now tell that that is only a vent to relive any overflow.
I got ahold of the tech at a local dealer. He said to try to remove some or part of the support brackets along the side of the tank. (See previous side view photo that shows drain vent). Once those brackets have been moved , peel back some of the protective skin and see if the fill hose or something elsemight have come loose. I have notice the last few times out, even though the tank was filled up, the “gauge” inside only reads 2/3 full. I did travel with a full tank and maybe with the heat (it was over 90) and the water sloshing around.