WoW Petopia Community

As always, I apologize for my poor English, I do what I can...

The other day, with my vulpera hunter, I tamed the elusive alpaca of Voldum, the one that gives a mount with a quest to give vegetables. I did it using the Shard of Nzoth.
Now after a week and a bit of searching Uldum, I finally found the friendly alpaca of Uldum, which also gives a mount when you give it some vegetables, but this time it doesn't let you tame it (although according to Wowhead it is), using the shard of the old god...

Why one yes and the other no? Is there some logic that I'm missing?

Was the first tame before the early release of the expansion? Some things are pretty buggy right now after early access got released, so I wouldn't be surprised if they made a few errors here and there like this.I know it's not exactly easy considering its rarity, but maybe try again a little while after The War Within is out and has had its first round of patches?