I have a male Beartic with 31 Attack and HP IVs with a female Cubchoo with 31 Defense and Speed. The Beartic is holding Destiny Knot. I've got almost a box full of Cubchoos now and I've still only gotten 2 31 IVs on their offspring. Am I missing a step in them passing off more than two IVs so I can continue to chain breed? Does the female need to hold one of the power items?
No, your just getting unlucky. If you just keep trying, you'll eventually get a 3-4 iv one.
Although, you could also try using the power item. It'll count as one of the five ivs being passed down, but you'll always at least have that stat passes down I believe. I recommend you keep doing what your doing however.
Edit: yeah, listen to flarg about the male parent idea.