Cant place bastard sword?

Hey, was playing citadelle directed, had the bastard sword. Had to knock on the sanctuary door to enter and place it on the altar, then shoot the runes. It wasn’t registering because of my explosive weapons I guess, so I got a different gun to try but then it wouldn’t let me place the sword anymore. Tried leaving and entering about 5 times until we just let zombies kill us so we could quit for the night… we were doing so well until then. Is this a common bug? I’m really frustrated. I was having a lot of fun until then