Washboard

Hi, I had the same issue and had to return it and they sent me a new one. There is supposed to be to be a valve stopping the water once the robot refills itself. Mine was not working appropriately so it woudl empty the whole tank if the robot was in the dock because it presses it to refill.  Hope it helps

The same problem

This ‘washboard abnormal water level’ notification on the L10s Ultra Gen 2 is usually related to a drainage or sensor issue rather than the dirty water suction power itself. There isn’t actually a setting in the app to manually increase the dirty water suction. Instead, the message typically appears when the dock detects that water is not draining properly from the washboard.Try the following steps:
1. Clean the washboard and drain filter – Remove the washboard and thoroughly rinse it, paying special attention to the drain holes and any mesh filters that may be clogged with debris or detergent residue.
2. Check the dirty water tank – Ensure the tank is properly seated and that the float or sealing components are not stuck or misaligned.
3. Inspect the suction inlet – Look inside the dock where the washboard drains and clear any blockages that could restrict airflow.
4. Examine the drain hose (if applicable) – If your unit is connected to a plumbing kit, make sure the hose is not kinked or obstructed.
5. Clean the water level sensor – Residue or scale buildup on the sensor can trigger false “full” readings. Gently wipe the area with a soft cloth.
6. Restart the dock – Unplug the dock for a few minutes and then reconnect it to reset the system.
Since there is no user-adjustable control for dirty water suction, repeated alerts after these steps may indicate a faulty sensor or pump, in which case contacting Dreame customer support for service or replacement would be recommended.