Nostalrius Begins - Quality wow vanilla realm (1.12)

Me and a buddy are both warlocks and did our felheart quest together and noticed that our Corruption wasn't stacking. There were no other debuffs so it can't have been near the debuff limit our corruptions would just overwrite each others.

Edit: Was with another warlock and corruption was stacking properly, why wouldnt it stack before? Nothing was different.

Perhaps you had different ranks of Corruption?

Different rank. Inform the staff of the bug