When exiting from the nether into the overworld, the game gets stuck on building terrain. I let it go in this example for about 10 minutes before quitting the game from the Xbox menu. When this issue first arose, it took a few minutes, but eventually put me back into the overworld, however parts of the map were not rendered at all. I have been unable to recreate that since.
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Thank you for your report!
We're actually already tracking this issue at MCPE-44815, so I will resolve and link this ticket as a duplicate.
If you would like to add a vote and any extra information to the main ticket it would be appreciated.
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