when you walk through a portal  atleast on realms. if any monsters see's you it will start to attack even tho you are still on the loading screen and if you are on a little older console. you'll most likely be dead before the loading screen is finished. that will sometime make it impossible to access an portal. 

there is properly a million solutions to fix this but an easy fix would be to do so the hostile monsters dosen't see the player till its first movement

normally i wouldn't care enough to write in
but both i and my friends are tried of losing our progress to a loading screen,
it has been in the game for years at this point so i don't know if you guys see it as a bug