I have this tool and absolutely love it! It definitely makes creating this pineapple block easy and perfect every time. I've made one pineapple quilt top and a bunch of pillows and square blocks for donations using this tool. I've had no problems with it.
Yes it's supposed to cut off corners and extra fabric since that is what makes the blocks square up perfectly.
If I were you, I would carefully go through the instructions step-by-step to make sure you're not doing something wrong.
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