Diagnosis
The built-in humidistat is not precise; it's more of a guide. The reading can be off by +/- 5-10%, and it measures right at the unit, not room-wide.
How to Fix It
Don't chase the number. Use a standalone digital hygrometer placed across the room as your truth source. Adjust the Midea's set point based on that. If the standalone reads 55%, try setting the Midea to 40% or 'Continuous' mode and see if the room humidity (per your hygrometer) actually drops.
If That Didn't Work
The unit may be undersized for the space or conditions. A 35-pint unit in a cool, very damp 1500 sq ft basement will struggle. Ensure doors/windows are closed. Check that the air filter is clean and there's at least 12 inches of clearance on all sides for proper airflow.
Heads Up
The unit's display shows current humidity, not your set point. The set point is the small number next to the % symbol. If the two numbers are far apart, the unit is simply working to close the gap. Give it 24 hours of continuous operation in a sealed room for a true performance test.