I tossed one stuck cup and lid in the garbage and bought a new set figuring my old one was just being difficult. Nope, new ones do the same thing. I bought this rubber strap set and use it regularly... shouldn't have to, but these cup / lids suction together so hard i hardly try now before getting the straps. Ya, i have to lay it down sideways on the counter... but it loosens them every time. What i have found is if the threads get wet, the suction happens more often. So don't over fill the cup. Dry threads, smaller amount of material, fewer sticky situations. good luck
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