This is now the second Shadowkeep quest which doesn't get marked as a complete. Happened with a previous quest, too. Can't recall what the name of that was.
Having done the 'Beyond' quest now 3 times, collected the artifact 3 times, used the full armor set (if that makes any difference)?. Always end up back to the orbit, and I can see that the campaign is still available on map.
Would like to use this opportunity to also say that I'm soon used more Googling around about how to play this expansion, rather than actually playing it. [b]This expansion is just absolutely awful.[/b]