Image should be viewable now...
I replaced the side strip grommet and after ~1Hr of hitting I hear a rattle and the grommet is broken the same way in the same spot. Again I do not recall shanking a ball.
I suspect when the grommet hole was drilled out, the tool head might have been dull so the hole might have sharp edges or burrs which might dig into the grommet enough to start a tear which after some hitting travels around the grommet until it cracks off.
This time the grommet is not split all the way through the hole so I will leave it but when I replace the grommets the next time I will take a small, round file and smooth out the hole first.
Gotta love modern quality control...