The first time you run logrotate with a new log configuration it doesn't know when the last log rotation occurred, so it just writes a status line in /var/lib/logrotate/status to the effect that it was run today.
When it subsequently runs the following day, it sees that the log is a day old and rotates it as expected. If you don't want to wait, edit logrotate's status file and goose the status date for your log back to the previous day.
When you run logrotate manually, it will work as expected
