DIAGNOSIS The filter access isn't super obvious. The washable filter is behind the front grille, which is a single piece that snaps off, but it feels stuck if you don't push in the right spot.
FIX Turn the unit off. Look at the top of the front grille, just above the display. You'll see two small indentations on the left and right sides. Press firmly inward on both sides with your thumbs while simultaneously pulling the grille toward you from the bottom. It should unlatch and swing open. The filter is a rectangular foam panel you can rinse under lukewarm water. Let it air dry completely before snapping everything back.
IF THAT DIDN'T WORK If the grille truly won't budge, double-check that the water bucket is fully removed first. Sometimes the bucket mechanism interlocks with the front panel.
HEADS UP Don't use hot water or any cleaning chemicals on the foam filter—it can degrade the material. Just a gentle rinse every few weeks. A clogged filter is the main reason for reduced airflow and poor performance.