It's the radiation but you need hot air to bake a pie quickly.
Divella pizza 66% hydration
45g salt - 0.5g fresh yeast for one liter
8h in bulk and 12h in ball (195g)
baking time 80sec.
The terracotta stone gives you much more latitude, no need to rush between the pies ! the first one was cooked with the stone deliberately too hot (above 500°)
the bottom wasn't badly burnt, still eatable, no bad taste in mouth.