Cheese burns

Cosmetic

Burnt cheese usually means a low-moisture, high-fat cheese given too much heat for too long, or placed too close to a grill element.

Ask yourself

#1
Low-moisture, high-fat cheese exposed to very high heat for too long
Generally accepted
Cheeses with less water to evaporate first reach browning, and then burning, temperatures faster.
#2
Cheese placed too close to a very hot top element (e.g. a broiler)
Generally accepted
Direct proximity to intense top heat accelerates browning past the point of control.

The same symptom has different answers on different equipment. Each branch below states how to tell whether it is yours.

Pizza in an air fryerGenerally accepted
How you would know: The cheese has blackened on the highest points within the first few minutes, while the base underneath is still pale.
The element is directly above the basket with very little headroom, so the top of the pizza — the cheese and anything mounded on it — takes the most intense heat and browns far faster than in an oven at the same setting.
Do now: Turn the temperature down and continue; do not lay loose foil or paper over the top, because the fan can lift it towards the element.
Change next time: Use a lower setting for longer, keep cheese and toppings spread flat rather than piled, and choose a pizza or slice thin enough to sit well below the element. For packaged pizza, follow the pack's air-fryer setting if it gives one.

Not fixable once burnt; scrape off visibly burnt patches if the rest of the pizza is otherwise fine

Match cheese choice to bake temperature and time, and watch closely rather than relying on a fixed timer near very high heat

Guides that treat this as an outcome to improve, an environment to work with, or a flavour to understand, rather than only a problem to fix.