Nostalrius Begins - Quality wow vanilla realm (1.12)

Recently had a little issue with my level 6 rogue toon (name is Aerlior, PvE server) where I went to go learn a couple spells from my class trainer in Razor Hill.
I click the spell to learn it, which is supposed to exchange my gold for the spells, and it ended up having the trainer rob my gold without giving me my spells.
This situation happened for a few minutes, where I carefully retried a couple more times. It later worked correctly, but ended up in me losing 5s total (should've only been 2s).
Now this isn't a big deal, as it is only 5s, but I just wanted to warn other players when learning spells. This very well can also happen when training riding, so be careful.
Any devs that can help me figure out how this occurs?

Anyone actually have this happen to them? I do recall seeing a thread somewhere of it.

Alright, I found out how this occurs.
You can see how the trainer sits inside of the hut. NEVER attempt to train whilst outside of the hut like I did, because the npc won't be able to cast the learning spell on you as you're standing abnormally above the npc and you're not in his/her line of sight. Instead, walk normally inside the hut and train from there.

Maybe :
Remember to Delete Your WDB (Cache) Folder

Ah, I already solved it, but thanks.