The hole is normal!
Since you're knitting stitches 4, 5, and 6, before stitches 1, 2, and 3, the yarn has to stretch, and you wind up with a little hole. I have storebought sweaters that have the holes, too. There's not much you can do about it, but the cable mostly covers it once everything's said and done.
You might just need to give it a few more plain rows so you can see the cable, but yes, pictures would help us resolve your knot.