After change to 13306, Galera logs error: Slave I/O: error connecting to master ‘repuser@:3306’

Working with Galera 25.3.23 on RHEL 7.3

Galera works good before. After changing the MySQL server port from 3306 to 13306, one of the node report error, after restart:

Slave I/O: error connecting to master 'repuser@<IP>:3306' - retry-time: 60  maximum-retries: 86400  message: Can't connect to MySQL server on '<IP>' (111 "Connection refused"), Internal MariaDB error code: 2003 

The other 2 nodes works fine after the restart.

Googled the web, but don’t find the way to specify the port number.

Also, if possible, please share the usage of the “repuser” ID.