If the lens of your Xiaomi smartphone is fogging up, it could be due to sudden changes in temperature or humidity. This happens when the phone is exposed to a cooler environment after being in a warmer one.
To resolve this issue, please refer to the following steps:
1. Keep the phone in a room temperature environment to let the moisture evaporate naturally;
2. Ensure your phone is not exposed to drastic changes in temperature;
3. If the humidity is high, a dehumidifier can help reduce condensation.
If the issue persists, you can contact the local after-sales service center for further assistance.