Using/Activating Boss Altars

I've been trying to complete the quest "The Passage", and I am at the boss altar needed to complete the thing. I am pretty confident I understand how it is supposed to work: I right-click the altar with the tribute items needed (in this case 4 Zombie Eyes). But so far the altar is completely unresponsive to any interaction I try to make with it. I hadn't seen anything about this being a problem for others through bug reports, etc, so I am going to assume I'm just lost. Any advice would be appreciated!

 

ideally you're right clicking just above or at the "altar" (enchanting table) with 4 zombie eyes in hand. if its still not working probably just switching worlds and giving it a second or two before right clicking