I decided to search for it myself. Got nothing on the apartment yet, but CBR made an article on what happened to Nightwing around the time of his marriage to Kori, which apparently took place around KnightQuest/KnightSend as Bruce couldn't attend because of his injury from Bane.
"After his marriage to Starfire in New Titans #100 in 1993 was interrupted, he was sort of in limbo for a year, with a few guest appearances here and there.
And after he was completely written out of New Titans, he had a storyline filling in for Batman post-Knight's End and Zero Hour. And then he was back to limbo for most of 1995 until finally he got a new costume and his first mini-series in late 1995. It was still another year before he gained his own ongoing series in late 1996.
However, a lot of the reasons for why Nightwing was in such a state of limbo state in the beginning of the 90s was because the original plans for the character fell through.
Originally, writer/artist Art Thibert was going to do a Nightwing mini-series that would run in 1992, concurrently with New Titans #93-99.
The series, co-written with Pamela Winesette, was about an alien invasion of Earth that led to Starfire being captured and Nightwing has to save her. The main point of the series was to establish Nightwing as an extremely competent hero, and to do so on the largest of scales - in front of the entire superhero community.
At the end of the series, Dick would have a newfound confidence and would ask Starfire to marry him, she'd accept, and this would all lead into New Titans #100, which would be the marriage of Nightwing and Starfire, which would be handled much like Donna Troy and Terry Long's marriage in Tales of the New Teen Titans #50.
Of course, the best-laid plans of mice and men often go awry, and in this instance, the editor who was driving the project, Jonathan Peterson, left DC for Image Comics in 1992. Thibert had already put off doing the mini-series for a time because of a commitment to Marvel for a Cable ongoing series, but he ended up dropping both series to ALSO go to Image Comics.
So the new editors instead had New Titans writer Marv Wolfman have a wedding ceremony go awry in New Titans #100 (the minister was murdered by a newly-evil Raven) and the character of Nightwing had a bit of a delay on his road to prominence."
https://www.cbr.com/comic-book-legends-revealed-195/2/
https://womenwriteaboutcomics.com/20...and-nightwing/
That's a lot more behind the scenes than I thought, and wow were they unlucky that Nightwing editor and artist just have to leave, but I wonder when Batfamily editor's plan to bring Nightwing back to their department comes in because Wolfman didn't have to break them up.