Is it permissible to pray at home if the Imam prays Fajr prayer half an hour before its legitimate time and refuses to change its timing?

The Imam who prays Fajr before its prescribed time should be advised gently and kindly, with the error explained through evidence. If he does not respond, and it is possible to remove him and appoint another Imam without causing discord, then that is what must be done. If it is not possible, then one should go to another mosque that adheres to the lawful time. If no such mosque exists, then prayers should be performed in congregation in a suitable place, even if it is in the home of one of the worshippers. If all of that is impossible, then there is no sin in forsaking congregational prayer and praying individually at the correct time.