Clean Slate Glitch?

Yes, that dumbass lightbulb every few hours is an intended feature. It's nexon's way of provoking it's players into buying tickets for the 'secret machine' to get rid of the lighbulb.

Your quest thing about the dead end quest is just comparing apples to oranges. You can't compare the two. Merely, the quest is unfinished because Nexon did not write the end of the chain. The white scroll returning the slot has no relevance to an unfinished quest chain.

 Unfinished?

...But I suppose it's an intended feature.