“I have seen nothing about it in any patch, why was this changed?”
Becuase it is a bug?
It was fixed in the patch that fixed the raid xp penalty bug aswell, people have reported this as a bug, a lot of people complained about it being possible on forums aswell.
I believe that boosting in Vanilla always gave less experience. Any kill involving an overleveled character would involve reduced experience.
I remember that just healing someone would avoid it. Allowing you to keep them alive whilst they’d fight 4-5 mobs
So in an ever changing world blizzard maybe changed something…what a shocker.Also OP if you going to claim something at least get some evidence/prof and also numbers and more information:
1.Level before/after
2.Time and date before/after
3.Print screen before/after xp bar,and mob xp
4.Maybe chek reddit(us forums,any other source) if anyone has some evidence and proff regarding this.
…so far we would have to believe you out of nothing.