Dear sir,

There's a glitch that allows to stay stuck in forever by placing bed under end portal in overworld then sleep on it.

After this we can't leave end in any gamemode either survival, creative, spectator, hardcore or adventure gamemode. 

There is only two way to leave by using /execute in minercaft:overworld  and set respawn then /kill or by going to spectator and do /kill.

Please fix this glitch in future minecraft version as soon as possible because it ruined many people's survival worlds and hardcore worlds.