This morning I went to do Aylaag quests on my main. I saw from the timer that I had 1 day, 8 hours to do them. I picked up the quests and completed them, then decided to ride the carousel before turning them in. After getting the carousel buff, I hearthed to Valdrakken, then remembered the Aylaag Windstone Fragment. I tried to use it, and it gave me an error saying that the camp was moving. I looked at the map to check the timer, and the camp icon/timer was gone. I flew to Ohn’ahran Plains, the icon/timer reappeared, and I was able to use the windstone fragment.
I then got on an alt who hadn’t done the quests yet. In Valdrakken the map icon/timer was missing and the windstone fragment gave me the same error. Flew to Ohn’ahran Plains and the icon appeared and the item worked. I then hearthed to Legion Dalaran, saw that the icon/timer were still on the map, and the windstone fragment worked.
So it seems like the windstone fragment is checking the camp’s status by looking for the map icon/timer. If it can’t find it, the item assumes the camp is moving and fails.