I wanted to add fuel to my 1991 - 52CPMY today. I filled the forward tank, and as can be usual, the fuel foamed back up to the filler plate. Shortly thereafter, some fuel dripped out of the Mid-Ship tank vent hose. When I went to fill the Center Aft tank, the Mid-ship fuel tank vent started to discharge fuel.
I attempted to fill two tanks, neither associated with the Mid-Ship vent, but both feed back from the Mid-Ship vent.
Can anyone offer any clues as to what is happening?

Hank J