sup, and welcome, WOLFE.
I kno exactly what you are talking about. My car also has the same exact problem: premature gas pump shutoff. I thought it was just the pump too, but when I tried other ones I got the same thing. Funni though, cuz the problem isn't constant, actually now, it seems that my car isn't having that problem. I recalled asking my dealer about this issue and they said that it has to do with oxygen in the tank. BMW apparently have a special gas tank that is airtight, but not sure what the real deal about that is. I assume it is some high tech method of preventing the tank from explodign? DUnno but anyways, it seems to fix itself overtime, at least for me.