Replication – MySQL thinks Master & Slave has the same server id, but it's not the case

Try to configure MySQL to perform unidirectional replication. I have the master set to server_id = 1, a replication user configuration, the binary logging enabled, the server_id = 2 slave and is logged in and waiting for an event. I am also using Workbench.

However, the master server has the following error …

Fatal error: The slave I / O process stops because the master and the slave have identical MySQL server identifiers. these identifiers must be different for the replication to work (or the -replicate-same-server-id option must be used on the slave, but this does not always make sense, please consult the manual before using it).

I can not find any reason for this error. I have seen dozens of tutorials, manuals, etc., and none of them explain what is going on.