Safety first: Remove the battery before inspecting the wand.

Check for blockages: Detach the wand and look through it toward a light. Push out any obstructions with a long, blunt object.
Inspect for cracks: Examine the wand for visible cracks or splits, especially near the ends.
Check seals: Inspect the rubber rings or seals at each end of the wand. Replace if missing or damaged.
Test without wand: Confirm that suction is strong in handheld mode. If so, replacing the wand should restore performance.

Cordless vacuum loses suction only when the wand is attached; handheld mode works fine.

Possible Causes