Many years ago when invisible zippers first appeared, I put them in several dresses. After a short time, they popped open at the waist. I was thin then and although the dresses were form fitting, they were NOT unreasonably tight. I replaced the zippers and never again used an invisible zipper where stress might occur.
I feel certain that I inserted them correctly.
Did they improve the design? Are they now more reliable? Did I miss something during a hot flash?
I haven’t wanted to take the risk and try them again. Am I the only one who had this problem?