Guild Wars 2

I purchased 4 Level 39 Major Rune of Mercy from the Trading Post. I applied 1 of them to a Level 60 Strong Banded Coat of Mercy. I am Level 50. When I apply it, it comes up with, “Upgrading an item will make it soulbound to you. Apply Major Rune of Mercy to Strong Banded Coat of Mercy? (Warning: The existing upgrade will be destroyed.)” I click Upgrade and I lose 1 Level 39 Major Rune of Mercy. When I check the stats of the armor piece, it has Major Rune of Mercy (0/4), instead of (1/4). Is this a bug? Any help would be greatly appreciated. Thank you!

Gotta equip the item, then it’ll show 1/4 (equipped)