My issue was marked as a duplicate of this issue so I will add my relevant data here to help.
Seed: -8434814575835167583
This world was originally created on the Xbox One Edition. The conversion to the new Better Together (bedrock) edition completes. However, the world is incorrect. There is a large body of water that cuts into the area surrounding the starting point. Other areas are incorrect as well.
I have attempted to re-convert after updating, playing, and saving the game again in the Xbox One Edition in case the update changed the save format. This did not work.
Original Xbox (Not S or X)
Xbox Insider Program (W/ the Preview Dashboard installed)
From:
Updated Version of Minecraft XBox One Edition (Date: 20170920)
Size: 256.6MB
To:
Released Version of Minecraft (Date: 20170920)
Size: 154.9MB
Thank you. I took a look at the linked issue and it looks like it is the same behavior (duplicate).
I did not realize that the chunks were missing and being re-generated. It just looked like the conversion had gone wrong wrong. That makes sense, though.
I added my details to that issue and will follow it until it is resolved to see if it fixes my problem as well.
Thank you,
=[Kevin]=