I have entered the End and slain the enderdragon, but I did not get awarded "The End?" achievement for entering the End, nor did I get "The End." achievement for killing the dragon (since the prerequisite didn't unlock).
I have since entered the End a few more times (through the same portal), but the achievement remains locked. I have completed all prerequisite achievements, and am using an unmodded version of Minecraft.
Related issues
duplicates
Comments
This bug is in Survival mode, not creative mode, so these 2 bugs are distinct, but should be merged.

Read the comments in MC-2097 , it doesn't matter if creative or survival.
Duplicate of MC-2097 , please use the search function to see if your bug has already been submitted. Currently over 30% of tickets are being closed as duplicate.