Rotation occurs when translating a bone when clamping is enabled

How can I prevent the rotation of the bone when attempting to translate the bone and while enabling “clamping to closest vertex”?

I am following along with a YouTube tutorial created by BornCG. https://youtu.be/5NlvgMYZgaY?t=25m

When BornCG translates the bones they do not rotate. When I attempt to translate a bone by selecting G then moving the cursor, the bone rotates 90 degrees. See the blue highlighted bone in the following two images. Notice the rotation of the bone 90 degrees toward you.



I am in the Ortho view and using “clamping to closest vertex”. After switching off the clamping feature, the bone no longer rotates when attempting to translate. However, use of clamping is desired.

The grid places a vertex in the centers of each individual mouth texture.


That is why clamping to closest vertex is desirable.