Overworld mobs are spawning both in the Nether as in the End. The World I was playing on was transferred from Minecraft Xbox One Edition to Bedrock, but I don't think that is the problem since I've just generated the End today. I know that this has been posted before, but I saw that it was marked as resolved and it isn’t, currently it’s still a problem. Do you know what might be causing this?

Thanks for the help.