It's possible that beans have become jammed in the grinder, blocking the mill motor.
Such a blockage can happen when the grinding degree of the mill is changed. Especially when adjusting from coarse to fine, all beans must first be removed from the grinder so that they do not get jammed in it when the grinding degree is adjusted. If beans get stuck in the grinder, an automatic lock ensures that the motor comes to a standstill and cannot run hot.
To free the mill from ground material residues and tilted beans, a deep cleaning is therefore necessary. You can find out exactly how this works in the PDF instructions attached here.