The problem is as follows: when killing any mob, the standard loot initially drops — gold, cloth, and other items. However, after just a few minutes of farming, the loot drastically changes — gold is replaced with silver, and cloth along with other valuable materials stop dropping entirely.
I tested this on different types of mobs — the result was always the same. I asked a friend to run the same test — he experienced the exact same issue. I also spoke with guildmates — they confirmed that they’re facing the same problem.
Farming becomes pointless: it’s impossible to gather even basic resources for crafting items. I moved to Pandaria to check there — and unfortunately, the bug occurs there too. The issue appears to be global — no matter where I go in Azeroth, the problem persists. It seems to be either a bug or a stealth nerf that hasn’t been communicated.