Reproduction steps:
1. Open the attached project 'Angular'
2. Open the available scene
3. Play scene
4. Observe the behavior in scene view
5. In the 'Cube' gameobject, disable the Constant Force component
Note: This is the desired behavior
6. In the 'Anchor' gamebject's Configurable Joint component increase the Angular X Drive Position Damper to any number above 5000

Result: Increasing the Position Damper from 5000 up to the maximum has no effect on the rotation speed of the cube
Expected: Having increased the Damper up to a certain amount, the behavior should be close to the one in step #5. User expects the Damper effectiveness to be proportional to it's value.

Reproduced with: 5.5.0b2, 5.4.0p4, 5.3.6p3