Saeco HD8769 does not grind

Hello,
my Saeco HD8769 no longer grinds. I heard how the motor turns, but in a much higher tone and it also did not come the sound of grinding beans.
At some point, then also came the error code 1.
Therefore, I had looked into the grinder purely, and it also really probably hung something in it. Looked like a nutshell or a piece of wood, or something.
Error code no longer comes, but the high tone is still there. And the auger (is that the name of the part) that feeds the beans out of the bean hopper is not turning.
I had now the entire motor / grinding unit times unscrewed.
The plastic gear that sits under the grinder has a slight rounding on the teeth. Is this normal, or is this turned off and is that the problem?
The motor and this spindle rotate in any case. So my first idea would have been the gear. Could I be right, or is the problem probably something else?

Thanks for the help

After I have the grinder now several times open and closed it runs / turns again.
For whatever reason.