If you change your username on the website, there is a period of time where you have a different UID than normal. This results in joining a single player world as second user. After an unkown peroid of time, your UID returns to what it originally was.
This can result in any existing world joined shortly after changing your username to initially appear like your world has been reset, or any world created during this time period to appear like it has been reset after re-joining later.
Hi!
Thank you for your report!
We're already tracking this issue at MCL-26207 , so I will resolve and link this ticket as a Duplicate.
I suggest also to browse through the main issue for potential fixes.
If you would like to add a vote and any extra information to the main ticket it would be appreciated.
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