All machines with thread cutters have this problem, because they must leave a little thread left, both top and bottom, after cutting. Most machines leave around a quarter inch of thread tails or longer. When you star the next seam, those tails get tangled, (the longer the tails, the larger the knot), so you really need to use a scrap of fabric as a "spider" or a leader piece, for that small tangle to fall on, then chain piece onto your project piece. Also, often machines are fussy about which brands of thread work best with the thread cutter. Some brands of thread will unthread and whip up, disappearing into the machine head when cut with the thread cutter. Like you, I was disappointed to find these problems, wish seller had disclosed them before the sale, and don't use the cutter as much as I thought I would. It's still a nice feature to have sometimes.