I just got my first apple tv Friday via ATT $90 deal, its 4K, anyways for some reason I had an apple tv device on mx900's second page, did what you did got the same results. But with Inteset 422-3 UEI made remote using code 02615, I can get it delete using the same procedure. I don't know what difference between the two code sets used in the different universal remotes? Hope you figure it out.