End portal and Elytra Wings issue

While fighting the dragon when it comes down to the center... to the portal.. and is vulnerable to melee attacks when it killed me and all my stuff dropped i could not see any of my stuff... it was there but invisible.. even the stuff that fell outside the bedrock portal shape... but upon walking around i could collect everything..

Now regarding Elytra... once i ender pearled through the small gateways to the end islands i could not use my elytra wings in creative or survival... and on coming back to the central island i still could not use them.. but on going back to the overworld they started working again..

i hope i was of some help... Cheers Devs !! ^-