Something seems wrong. Everyone else’s bowl doesn’t leak so maybe you’re pinching the gasket as you install, you’re getting the wrong gaskets or there’s a gouge in the surface of the bowl or carb. Possible you have an incorrect bowl on those carbs which require a different gasket?
And +1 on the fuel level shouldn’t be high enough to leak at the seam unless it’s sloshing around and leaking or the bike is on the side stand.