gear showing up in invintory , but upon entering the end, did not show up in HUD or allow me to use the elytra

so, I have this survival world, right? and I'm in the late game, like, LATE game, but when I go to the end, my elytra won't work, and my armor, (including elytra) is showing up in the slots, and I can move them, but the armor slots may as well be 4 more inventory spaces!