AddForce causes object to bounce when moving onto other identical platform

Hi all.

I have a basic capsule with collider, rigidbody attached. The rigidbody uses gravity and is not kinematic, and
the rotation is frozen on all axis.
If I use AddForce to send it in a direction on a stretched cube, everything behaves as normal.
If, however, I create a pathway made of the default cubes, one after another, lined up perfectly as far as the position in the inspector is telling me, The capsule bounces every time it reaches the next cube.

I was originally using some slightly more complex shapes, but pared it down to this to test what was going on. Why does it bounce between each one? If they're lined up just right in the inspector, the capsule shouldn't be hitting anything, right? I can only presume that they're not lined up as nicely as I'm being given to believe.
Are these assumptions correct, and if so is there a way to fix this problem?
Am I simply doing something else wrong?

As always, any help would certainly be appreciated.