You need to properly secure a coverstitch seam, because, unlike a sewing machine, you cannot backstitch on a coverstitch machine. So if the thread ends are not secured, the seam will unravel quickly. Here is an overview of the two most common methods: The clip and pull and the secure-by-hand method. https://www.thelaststitch.com/how-to-secure-a-coverstitch-seam-step-by-step-tutorial/
