grinder regulator broken

Hello,
For a few months I have the machine and am completely satisfied!
Today my friend wanted to adjust the grind and has of course NOT made during the grinding process.
He also said it went incredibly difficult, suddenly something cracked and since then the wheel can be turned without any problem without any resistance.
The machine still works and I notice no difference from before.
Nevertheless, I have the feeling he could have "broken" the regulator, since it is now so easy to adjust.
I'm also a little afraid that this may give permanent problems with the grinder or something.

Does anyone have any idea if the regulator can be easily replaced?

Thank you very much, love!