I got my team to 80, and i've started working on Glory of the Hero. Whenever i first go into an instance, it says there's a lockout (today it was 18 hours when i was doing it).

If i clear the instance, i can't requeue for the instance through the tool, but if i wait a while i can go to the instance directly and the mobs respawned.

Is the purpose of the lockout to prevent the use of the tool? Are the bosses not respawned? What exactly does the lockout do?

I'm confused.