Air pocket on Matone Cupola

Hello BrickWood oven!!
My wife and I poured the 28” cupola last weekend and I started taking down the foam form. Unfortunately I noticed on the outside an air pocket that formed and I could see through it. Can this be fixed by mixing more refractory cement and patching it? Can it be fixed by patching it with refractory mortar? Or do I junk it and start again?
The pic below doesn’t show the void but it’s further back on the left side. I failed to take pic at the time.
Thank You in advance.