Why can't my Xiaomi Microwave Oven cook food as fast as the manual states?

For your reference, here are some reasons that cause the difference:
1. Check the instructions to see if they are being followed exactly and identify the reasons for different set times;
2. The recommended set times are for reference only. To prevent overcooking, please master your microwave cooking techniques;
3. The size, weight, and shape of the food can affect the cooking time.
Note:
If the voltage is lower than 210V, the heat will become slow. if the oven door is not closed properly or the voltage is lower than 190V, the heating will stop. Please refer to the instructions and adjust flexibly.