Spirit 31G gray tank question

[Timlib59]

I bought a new 31G over the winter. Getting ready to take it on its maiden voyage, ran the water and immediately found a leak in the drain system. After investigating, the flex hose that goes from the hard pipe into the top of the gray tank had popped out. This is on the slide from the kitchen sink drain. It does not appear at first glance that there is anything that holds the swivel in the top of the tank. Does anyone know if this is in fact the case or is there something missing. Seems strange I can lift the sleeve attached to the flex hose out of the top of the tank? Thanks

[BFlinn181]

If you go to the Winnebago Resources website, you should find manuals, plumbing, and electrical drawings for your RV. You might find if a fastener or clamp is supposed to be in the connection or not.