Maintenance mode for NE (i.e. NE BLACKOUT) is not turned off immediately

We succeeded in setting on the fly an NE in blackout(maintenance) mode, so incoming orders insisting on that specific NE are pending in 103 status in ASAP. We used SSP_add_blackout stored procedure for this, setting a maintenance period of 5 minutes.

The problem is, when we put NE off of blackout using SSP_del_blackout stored procedure, or when the blackout period is over.

The normal functionality of the NE is restored not immediately as expected, but after some time (minutes) after we apply SSP_del_blackout or the blackout period is over.

So, please advise if this behavior is the one expected (blackout period is set off not immediately), how much is the default delay (if any) and where we can configure this delay (if possible)