I used my elytra to go around my island then suddenly hit a water current. i couldnt move for some reason so i /is go but when i went to my island spawn, i got stuck on my elytra form and i fell off the void with ALL my best stuff. in case u dont have an idea of what best stuff is, its basicly all dia tools with full enchantment, with elytra only mending and full dia armor with best enchantment including mending. this made me so y! I do hope you have the ability to see my past inventory for proof.
When you were flying with elytra your hitbox changed to <1m high (normally 1.8m), this hitbox change plus warp quirkiness makes it so that if you warp to a place which is only 1 block thick you will fall through it. Same thing happened with the old /is spawn on the bridge to pvpmine where you also fall through the bridge into the void.
