Quest items from Ancient Vows cannot be used properly to complete the quest

On the quest Ancient Vows we're asked to insert the 2 relics inside an altar to complete the quest. But the altar's interface doesn't work properly. It displays the slot where you need to put the relics when you mouse over the altar,but this interface isn't interactable, you cannot click on it and it will disappear when you move your mouse away from the altar, making it impossible to slot the relics into it when you go grab them from your inventory.

I also have this exact problem. I have no idea how to use that altar. I can drop the relics on the floor, but doesn't do anyting. Can't drag it onto the altar interface, since it disappeares

same issue

cant delete or abandon quest

There is a way, if you mouse over the altar and hold alt the interface won't disappear and you can drag the items to it. Still a bug that should be fixed