Ladder in sock

here’s a question – I noticed on the Regia sock I made (one down, one to go) that there is a line going from the heel to the toe on the sole of the sock. It’s the transition between needle one and needle three. I don’t know why it happened on this sock, I’ve made this pattern before with no problem.

The other socks from this pattern are made from alpaca/wool, that’s very soft and fuzzy. That may be why there’s no ladder on that pair of socks. The Regia yarn is very pretty, but it has somewhat of a hard texture, and I’m wondering if that’s what caused it. There is no ladder on the other two transitions. Not sure why. The place where the ladder is is between two pieces of stockinette. The other two transitions are between stockinette and pattern stitch, so maybe they wouldn’t show.

I thought I snugged up the yarn enough each time. What do you guys think?

I’ve just started knitting in the round recently and noticed that once a ladder gets started --it’s going to continued until you move the knitting over a couple of stitches to a new location between dpns. I have been able to kept ladders from happening by doing this.

I never thought of that! Thanks!