I was going through my achievements and stumbled upon the “Friends In Places Higher Yet” that I had finished in 2019. The achievement required me to have the Heart of the Nightwing mount, so I went to look for it and saw that it was not in my collection.
After submitting a ticket, I was told to post here and I could possibly get some help recovering my missing mount, I even sent a screenshot showing the achievement and the date it was earned.