If it "Lurches" in time with the engine then you have a fuel deliver problem.
If it lurches without any change in engine rpm then you have air in the hydraulics and they need to be bleed.
Note "they" both sides.
The QC on Craftsman now days is on par with stuff from China.
And the pre delivery down here is non existent.
Just done 3 Craftsmen all with less than 100 hours all had the decks nearly 2" lower at the front all had bent blades ( wonder why ? ) all had wrecked spindle bearings and all drove really crocked no matter how much I adjusted them