Why does the Xiaomi Oscillation Electric Toothbrush Pro display an alert for Damp charging port?

If the screen of the Xiaomi Oscillation Electric Toothbrush Pro displays a "Damp charging port" alert when connected to the charging cable, it means there is liquid in the port. Charging in this state can cause a short circuit. Please ensure the port is completely dry before charging.
To dry the charging port, please refer to the following information:
1. Unplug the charging cable;
2. Hold the toothbrush with the port facing downward and gently shake it to remove excess moisture;
3. Leave both the toothbrush and charging cable in a well-ventilated, dry area until fully dry. Once dry, try charging again. If the alert still appears, allow more time for it to air out completely.
Note:
Do not use paper towels, cotton swabs, or similar objects to dry the port, as these can introduce foreign particles.