World not fully synced

Troubleshooting the network would definitely help with the situation, first thing to do is go over the following steps:

Settings > Network Settings > Advanced Settings > Alternate Mac Address > Clear it and the console should restart. It would definitely help if you could restart the internet router while the console is restarting.

After going through the troubleshooting steps mentioned, I invite you to perform a quick power cycle by turning off the console and then unplugging all the cables. After 2 to 3 minutes, re-plug them back again, then restart your console.

You need to make sure to go over the steps mentioned here as well => Troubleshoot your Xbox One network connection | Xbox Support

Here are some tips on how to transfer your world if you are left with that choice => Transfer Minecraft worlds on Xbox consoles – Home

THE WORLD IS NOT FULLY SYNCED OR HAS BEEN CORRUPTED TRY PLAYING THE WORLD ON A CONSOLE WHERE IT HAS BEEN..

Previous device was an original Xbox One. Unfortunately, once I got the One X up and running (and tested to see if several games synced saved game data properly) I wiped the other unit in preparation to sell it. Sounds like I might be out of luck. Just
seems weird that all other worlds (both his and my other kids') synced fine. It's just this one that's corrupted.

I have previously played Minecraft on my Xbox One S, and when logging to my account on my new Series X, my worlds do not load, and i am greeted with the error. ‘The world is not fully synced or has been corrupted. Try playing the world on a console where it's in a good state and try migrating it then.) is there a way to fix this? As the world works on my old consol

Many Thanks,

Bob

Hi Bob,

I am sorry you're experiencing this issue enfortely we can't support that areas we can only advise you to contact Minecraft Support.

Thanks,

Did you have the Minecraft Beta on your old console?