Sounds like they may have gotten one of the buss cables to tight, or the wrong one tight. Some bows have one cable tighter than the other, to offset the pull of a cable slide.
over tighten the wrong one and it twists the limbs the wrong way, making them work against the natural torque of the draw cycle.
Or they removed an idler or cam and didn't get shims or bearings replaced quite right.
Hope they fix it before the season for you.