When entering the End Endermen attack you right away when you arent even looking at them! They knocked my brother off the edge as soon as we finally made it to the end, and he died with all his items! They do it in the over world but not like this. They just auto attack. Please fix this bug is terrible!
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I've been killed by ender men that I never even saw, let alone looked at. Didn't even know what was attacking me until I got the death message
Their teleportation in bedrock is way too fast, able to teleport behind a sprinting player, strike, and teleport away before they can even turn to see what hit them. There is no fleeing from an angered enderman unless there's a 2 block tall space to duck under. And they seem to randomly anger without any provocation. It makes me wonder if they suffer the same problem pigmen do, where any damage taken is blamed on the player, even if the damage comes from other mobs.

that happened to me as well i was trying to build stairs to the end city dimension they attacked me for no reason

This is still happening in 1.2.10. It makes defeating the ender dragon almost impossible when constantly getting blindsided by endermen.
Note that this bug was introduced sometime around the 1.1 release. I defeated my first ender dragon on Windows 10 Bedrock before this problem cropped up.

Confirmed on W10 Edition
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However, this issue has been temporarily closed as Awaiting Response
Is this still an issue in the latest version?
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This ticket has not received a response or been updated recently, so is being closed as Cannot Reproduce. If you feel this is still a valid issue then please comment, or create a new ticket following the Issue Guidelines.
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Reopening to resolve as a duplicate of MCPE-23544.
Related to / duplicates MCPE-22150