Loss of overworld progress after returning from the nether.

Played in my xbox one converted world for several hours. Decided to check out the nether from my existing portal. Went to the nether for a few minutes. Upon returning from the nether back to my home in the overworld I noticed that several hours of work I had done before entering the nether was gone. I built an automatic egg collector before entering the nether which is all gone now also the materials I used to build it were gone. Also found a dungeon before entering nether and took the loot out of the chests. After nether I went back to same dungeon. New items were in the chests and previous items collected from dungeon are gone. Shortly after this the game crashed with an error message.0x080040200

I am playing the better together update 1.2.0. It doesn't tell me which version I'm playing so I'm not sure if it's 1.2.0.31. It only says 1.2.0

Update: Today I entered the nether portal again and during loading the screen went black and I heard nether sounds. Then the xbox turned off. I reopened the world and I spawned into the overworld at the last save point before entering the portal.
I entered the portal again and this time successfully spawned into the nether. Couple minutes later the xbox crashed with the same error message. I restarted the xbox and opened the world again. I spawned into the nether in front of the portal.

After that point, I've gone back and forth through the portal several times successfully with no more crashes or loss of progress.

I guess the more I use the portal the more stable it becomes? I assume this is a problem for xbox converted worlds. My converted world is large, 177 megabytes because I explored alot before converting. Not sure if that helps or not.

Thanks for fixing so many bugs!! 🙂