The charging port itself is waterproof, so operating the Pool Cleaner without the charging port cover will not cause water to enter the device or damage the charging port.
The charging port cover is mainly designed for:
Dust and debris protection
Preventing accidental short circuits during charging
It is not designed to provide the waterproof seal for the charging port.
If water remains in the charging port:
1. Do not charge the Pool Cleaner while water or moisture remains inside the charging port.
2. Gently wipe or allow the port to air-dry. Make sure the charging port is completely dry before connecting the charger.