If you don't stay in the sector to keep it awake [AFTER YOU KILL THE LEVIATHAN] the levi sector disappears within 10 minutes (or less). It should remain intact until the hive regenerates.

More of a suggestion than a bug, but +1

+1

And the levi drop should despawn normally just like any other drop.

i suppose you are right meridian, though i seem to recall the ring persisting longer in the past. ill make a suggestion post.

It used to stay up way longer than 10 minutes indeed.

It did used to stick around for a lot longer, because it always used to be in one place. You are remembering before the new* missions that involve killing hive.

*new isn't that new, but in a VO perspective 2010 is new.