I’ve heard from people with all brands of interchangeable circular needles with this problem….a sharp edge on the needle part when attached to the cord. Here’s my tip/solution:
Place a dab of white glue (regular Elmer’s/school glue type)….very minimal, and spread it out smoothly. Allow it to dry at least a couple of hours. If you still feel some sharp edge, apply a little more until all you feel is a smooth glue bead.
Now those sharp edges won’t fray or catch on your yarn as you knit.
When you’re done, simply unscrew the needle as usual - the dried glue will come off easily.
Make sure glue doesn’t stick to anything as it dries. I like to stick it in some yarn/dishcloth to keep it in the correct position: