Confusion about sleeve cuff

I am just not getting it! While I successfully sewed the collar stand, I cannot seem to sew the sleeve cuff and facing together as instructed. I've looked at the instructions and the sew-along carefully a couple of times and tried and ripped out. It is the part where we are to re-sew the 1 inch seam that previously attached the interfaced cuff to the sleeve.I roll the sleeve placket away. Stitch to the dot and then continue sewing around the curve up to the top dot or beyond. What keeps happening is that when I turn it, the cuff facing is caught in the 1 inch portion and will not allow the placket to lie flat. What am I doing wrong? Help!