Bug reproduced in version 4.3.0b5 (19fb00de019e)

Steps:
In this example, the character controller on the "Character" game object has a height of 1.7, a radius of .3 and a step offset of 0.5. The gap in the red arch is 2 units high.

In the demo, you can press the "up" key, and the capsule character will be stopped by the gap. Continuing to press into it will eventually sent the character through.

This behavior can be completely removed by setting the step offset to 0, however, that is rather undesireable.

My desired behavior in this instance is that since the character collider's capsule is smaller than the gap, the capsule should have no issues moving through the gap, no matter the value of the step offset.