seems like there should be more to it
You might be missing a piece. There is a vent hose-to-vent connecter that's looks like this:
View attachment 87912
Various types and styles exist. Mine is open in the center without the louvers. This sits behind the exterior vent plate. They are about $10 at a marine store.
I believe this is the case, but even if that connector is missing, the wire that gives the hose it's shape should "thread" into the hole in the vent collector box and keep it in place. This is what I did for my bilge pumpe hose with a collector box that is also missing that connector.