Yeah, this one's common. It's probably not broken—it might just be in the wrong mode. The default mode is BoostIQ, which is smart, but sometimes you need to force max power.
First, grab the remote. Look for the suction power button; it usually cycles through icons. You want to make sure it's set to Max mode, not just the standard BoostIQ. Max mode locks in the full 1300Pa suction for the entire run. BoostIQ will *usually* kick in on carpet, but forcing Max mode guarantees it.
IF THAT DIDN'T WORK: The filter and dust bin are likely clogged, which murders suction. Empty the dust bin completely. Then, take out the high-performance filter and tap it firmly against your trash can to dislodge fine dust. Don't wash it unless it's explicitly a washable filter—just dry clean it. Also, check the main brush roll and remove any wrapped hair or strings.
HEADS UP: For best results on a mix of floors, just leave it in BoostIQ mode. It'll automatically ramp up to higher suction when it rolls onto the carpet, then quiet down on hard floors.