I do not think you're at fault here, and I do not believe that your account is being affected by a bug. The chance of finding the pendant is one of the many things in this game that's heavily reliant on RNG, and it's not uncommon for players to go several hours without finding one.
Make sure you haven't already found one, as you might have already found one and learned the enchant spell. You could try enchanting a ruby necklace, to see if it works.
If that isn't the case, keep trying. Hopefully, you'll find one soon.
31-Jan-2021 16:25:49