I’m not 100% sure this is a bug. However, I’m pretty sure I used to stealth in and ‘steal’ treasure chests from someone of the other faction while the person was clearing nearby mobs.
Now the issue I’m experiencing in Classic: Whenever anyone is fighting a mob nearby a treasure chest, I will become tagged for ‘in combat’ when trying to open the chest. Basically, it’s impossible to open a chest if anyone is fighting a mob nearby.
I can see how this may be something implemented to counter the ‘theft’ of chests. But this wasn’t part of Vanilla AFAIK. Is it a bug, or something Blizzard deliberately implemented? It’s sorta annoying, as it just causes people to stand next to the chest and spam right-click on it, waiting to become ‘out of combat’.