According to the wiki, "In Bedrock Edition, 3 strongholds generate within a ring of radius between 640 and 1152 blocks. Other strongholds will generate randomly throughout the world."

On certain seeds, this is apparently not the case. Specifically, there are no strongholds generated within 1152 blocks (presumably of 0,0).

Repro Steps:
Generate a new world using any of the seeds listed below
Use the command /locate stronghold
Notice that the location is outside of the 1152 block outer limit

This is an issue on a world I created on Xbox on 1.2. Screenshot and other seeds besides first were all generated on Windows 10 1.7.1

Example Seeds:
-1009229477 (Tested on Windows 10 Edition 1.7.1 and Xbox One 1.2)
-1639517742
-523533971