Help! Yarn runs across cables!

I’m a beginner knitter and am making a simple scarf to practice cables. Occasionally, a long strand of yarn will run through a cable horizontally and I don’t know why this is happening! I’ve attached a photo and circled the places where it’s happened so you can see. It only happens on one side too.

I’m also wondering why, in this 2x2 pattern, there is more space on the right side of each cable. Is it because I’m knitting so tightly?

I know the knitting doesn’t look very good – sorry! I’m learning!

The long strand of yarn is really the crossed knit stitch, unless you’re doing a YO between working the sts on the L needle and the cable needle, or somewhere else. Yes, it may be that you’re knitting too tight. Don’t work cables tight, keep them loose so they can stretch; if they’re tight they’ll pull on the adjacent sts and cause more gaps. Loosely knit the stitches will relax and fill in the gaps.

Welcome to Knitting Help!
The cable actually look quite nice. Yes, loosening up on your tension will also help with the tightness on the left of the cable and looseness on the right. You don’t need to pull the first two cable sts tightly up to the sts on the right needle. You can leave a small gap at this point.
If you find that the stitch on one side of the cable becomes too loose, there are some solutions for that here.