Yeah, this one's common. The usual suspects are clogged filters or a hidden blockage. First, unplug.
Check for blockages in the wand, hose, and the main airways. The wand releases from the hose with a button. Also, remove the bin and check the hose connection at the base. There's a clear inspection panel at the bottom of the bin recess on the machine; lift it and clear any debris.
If the airways are clear, your filters need washing. You have two. Filter A lives in the bin handle—push up the catch on the front of the handle to lift it out. Filter B is under the ball cover; turn the lock in the center of the ball to release the cover. Wash both only with cold water until the water runs clear.
Here's the kicker: the filters must dry for at least 24 hours in a warm, ventilated spot. No tumble dryer, microwave, or flames. Using them damp will wreck your suction and can damage the motor.
Do this monthly to keep suction strong.