Healing was Damaging

PrincessTrashcan

My Brother who is a mage started taking damage at the Ruins of Aela. It was consistent damage and we were confused. After I tried healing him, we released it was my healing doing the damage. The DoT was my Cheerful melody which we figured out after the fact. I was using quick wit to test.
We both relogged and left party to see if it would help. I fully restarted game and it did not help. He fully restarted and it also did not help.
He died and after it was fine.
We were on the platform where the one star Bone Crushers spawn for the record quest when it started, just killed mobs while waiting.
Even when we would use his Health Salva it would hurt him.