Not Burning a Wood Fire Pizza

A pizza burning on top while being undercooked on the bottom can be caused by uneven heat in the oven, as well as a pizza being overloaded with toppings. The former can be an issue with the oven itself, or can indicate that you are not drawing enough hot air over the top of the pizza. The latter is self-explanatory.

A trick sometimes used by pizzaiolos to prevent the bottom of the pizza from burning when the top has not cooked enough yet, is to lift the pizza closer to the top of the oven using the peel. This way, the top of the pizza gets some extra heat, while the cooking on the bottom slows down.

This image, which stems from a pizza oven manufacturer's Instagram post shows what I mean. The post also explains what is happening, and introduces the wonderful term "doming" for this practice.

When you write that the temp was registering 375C with the built in thermometer, I am assuming that is the air temperature near the top of the dome. If you are burning the crust, the surface temperature is likely much higher. You could check that with an infrared thermometer. The answer from @LShoon is accurate. With a pizza oven you really need to keep an eye on things, as the process is active and moves quickly. However, you may be making the surface too hot, and could try backing off on the intensity of the preheat, checking to see that the surface is in the 375C to 480C range.