DIAGNOSIS: You're using the wrong blade or loading ingredients in the wrong order. The standard extractor blade needs liquid to create a vortex that pulls solids down.
FIX: Use the extractor blade (four flat wings) for smoothies. Load in this exact order: liquids first, then soft ingredients (yogurt, banana), then hardest/frozen items on top. This creates a vortex that pulls the frozen stuff down into the blades. Don't fill past the MAX line. Use the 'Pulse' function a few times at the start to break up the vortex lock.
IF THAT DIDN'T WORK: You might have a worn or dull blade. If it's over a year old with heavy use, the sharp cutting blades can lose their edge, reducing blending efficiency. Compare it to a new one—if the edges look rounded, replace the blade assembly.
HEADS UP: The milling blade (single, sharp S-shape) is only for dry grains, spices, or coffee beans. Using it for wet mixtures won't create a vortex and will leave everything chunky.