Slow Set 7 not fully curing?

I just received a new batch of Slow Set 7. The parts I've made so far are not fully hardening/curing. The parts are soft and pliable even after curing in the mold for 3 or 4 days. In previous batches of this product, the parts cured in less than 1 day to a complete hardness. I tried both the volume and weight method of measuring to be sure both products were measured properly.

Seems I got a bad batch. Does anyone have any suggestions?