I noticed that while in the nether endermen (when aggravated) wouldn't teleport to attack me, I was thinking that it was probably because of the nether ceiling but then again, while in the overworld (without a roof above my head), endermen (when aggravated) wouldn't teleport to attack me but instead teleport away (most of the time) and make the aggravated enderman sounds. Endermen also only ran to me (if they could and only when I was in the nether) to attack me.