Spalling/Chipping on Oven Floor

[crbuck]

I just had a Premio2G installed. After curing the oven and then two great pizza parties, the floor of the oven is chipping/cracking. After looking at the installation guide, I have some concern that the installer used mortar between the floor and the inner dome, which appear incorrect. He also seemed to use it between at least some of the oven floor bricks. I've attached some photos, which I've annotated. Any thoughts/ideas about what is going on and whether I should be concerned about the chipping?

I appreciate any insight anyone might have.

Thanks!