Laser Rotary Pro free wheels

Falcon 2 40 watt laser and am using the rotary pro kit, did some regular tumblers with it but when I try and do a coffee mug with a handle it will not hold at “zero” the handle causes it to rotate so the handle goes to the bottom (hitting the base), then the rotary will not come back up when I try and either frame the graphic or actually laser it. Is there a weight limit? The mugs are nothing exceptional, just insulated stainless steel coffee mugs with a handle. Any suggestions or clarification, please let me know, thanks!!!