Safety first: Remove the battery and detach the floor head.

Clean front edge: Inspect the front lip of the floor head and remove any lint or hair buildup.
Check squeegee strip: Look for a rubber strip along the front or rear of the head. If it is worn, torn, or missing, replace the strip or the entire floor head.
Clear side channels: Clean the side edges and any small air channels that may be blocked.
Adjust technique: Use slower passes and overlap strokes, especially on thicker carpets, to improve pickup.

Vacuum leaves lines of debris behind the floor head instead of picking everything up.

Possible Causes