Service Time Blocks - When/what deducts time from a time block?

Can any of you guys tell me what triggers or when does work time deduction occurs on the service time block assigned to a location?

I have set-up an evaluation to test this feature and even when it is configured as the documentation states, when I create a ticket, add a note with work time defined and save it, the displayed service time available under on that location doesn't change (neither the one displayed when a tech is opening a new ticket on the ticket details tab, or the one displayed on the service time blocks definition on Locations-><selected location>-> 'Service Time Blocks' Tab).

Does it take place every "x" time period? when the ticket status changes to something (I already test changing to 'resolved' and confirming resolution,  and manually set a ticket to 'closed'?)

What else is it needed to enabe this deduction on the blocks?

Thanks for your help!