Bad Collisions: Infinite Bouncing

Unity 5:

I've looked at many answers but found no solution. I am dropping items into a box composed of 5 cubes with box colliders and the parent has a rigid body. The box is not kinematic nor affected by gravity. Each object being dropped has a rigid body and either a box collider or sphere collider (no mesh colliders) and rigid bodies. They are all set to Continuous or Continuous Dynamic detection. I've played with all the Physics tolerates (bounce threshold and contact offset) and adding materials to them with "0" bounce. I've also tried implementing the "Don't go through things" script, yet sometimes they do anyway. Everything seems to be penetrating and kicking back violently. I am not altering the transform or velocity of anything directly, it is pure physics. A video is here:

https://slack-files.com/T04CAHT50-F04CFDN4Y-ec67434da7

Any help would be greatly appreciated.