This happened when I was trying to get into the realm and because it was taking so long I decided to close the minecraft and re-enter, but when I did that my character had already entered the realm but static (my friends sent a picture of how my character was). When I tried to enter the game it said that my account was already being used to play in that world.

• I tried to join on the cell phone, disconnect my account and a few more things but nothing worked.

• I can enter into other worlds and servers, only this realm says that my account is being used to play in realm.

Obs: I still "I am" in realm (12/28/2018) I will ask the owner to restart so that I force the exit of my character. P.S:  restarting realm worked because it forced the exit of my character 

As it happened:

Loading the realm I closed the minecraft (because it was taking too long), so my character entered without me playing and consequently when trying to enter the realm appears a warning saying that I am already playing.

Update:
It happened again, with me twice and with another member of the realms. Please fix this.