If you do any changes in the console, 'Apply' button becomes active. But if you even close the console by pressing 'No' button and reopen the console again, 'Apply' is still active.
It is done by design. Changes in the console are being written immediately, but it affects only Database. DB has the changed value whereas Master Publishing Agent does not till 'Apply' pushed.
To revert changes back you have to press 'Apply' and then follow to RAS Console> Administration> Settings Audit
Additional information about this feature can be found in Administrators Guide on page 282.
NOTE: Settings Audit is available only since RAS v16.5 and higher.