The issue may not be the bowl itself but how you pack it. Vortex bowl holds a different volume of tobacco and, due to the spire on the vortex, the amount of air going through the coals and foil may differ.
You'll need to play around a bit and figure out what specific things you need to do differently when packing the clay bowl. That means trying out different hole patters, packing density, how high you pack, number of coals, etc.