Diagnosis
The primary filter is saturated and not allowing air to pass. This happens when the post-motor HEPA filter is cleaned, but the pre-motor foam filter is neglected.
How to Fix It
1. Remove the dust cup. Locate the flat, rectangular foam filter seated against the back wall of the cup compartment.
2. Remove the foam filter. Rinse it thoroughly under cold water until water runs clear.
3. Squeeze out excess water (do not wring). Let it air dry completely for 24 hours.
4. While the foam filter dries, also check and rinse the post-motor HEPA filter if needed.
5. Reinstall both filters only when completely dry.
If That Didn't Work
Check the inlet to the dust cup from the base for a large, compacted blockage that prevents debris from entering the cup entirely.
Heads Up
Never run the vacuum with a damp or wet foam filter. This can damage the motor and will instantly kill suction.