for the past 10 or so nights I have been going to kill ender men, but I have noticed that whenever I reload a chunk entities appear exactly where I left them. making it extremely difficult to open the end dimension as entities in the caves remain and add to the mob cap on the ground. this is also in effect in the nether dimension e.g. ghasts will always remain until a chunk is reloaded if not killed. I am playing on the most recent version as of 12 OCT 2019