There should be 1/2" of clearance between your crumb tray and the air assist. If it’s hitting 1/4" material that’s flat against the tray, something’s off, but the fan being at the wrong angle is one of the last things I would suspect.
In addition to the suggestions already made above, I would say make sure your foam is fastened down to the tray so it can’t lift when air blows it. You can use thin magnets or Honeycomb bed holdown pins.