This is my favorite End Boss and I like to kill him all the time. The problem is that Earle can glitch through the walls and floor of the room.
For the floor glitch, It looks like a melee attack can activate this glitch with the Thron Armo because sometimes the glitch star when I attack him. Then he just fooling constantly or have of his body is underground or floating on the roof.
The wall glitch can be active for the same of the floor on and fire him to but only if he is been attacked against the walls. Especially when he appears.
The only safe place to attack him is on the platform. This Bug has been for a long time now.
I will make a report on Bethesda.net