^-When I went back to the world that I recently uploaded to realms it was reset back to when I first started playing the world on the new minecraft. All progress lost. Another possible reason what caused this is that right before I loaded it up I went on the old XB1E version. I didnt load up any worlds, just went to the world list....
Luckily I downloaded the realm version that I uploaded earlier and everything was fine.....-^

Please figure out what is causing this and fix it im not truing to lose progress next time after maybe playing for months.--
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Edit: Ok, I have been troubleshooting this issue all night, testing what happens in all different kinds of scenarios and pinpointed the exact cause of this and also found out the problem was not what I thought it was at first....

So, this occurs whenever you join someone else's realm, or a server. You go and load up your converted world that you've been working on and you happen to load up your pre-converted position, inventory, and enderchest. So pretty much it reverts back your player data. BUT, the world edits are untouched and are saved including chests from the last time you played.
So, now that your with your old player data you can fix this and go back to your current player data that goes along with your world by simply restarting the game. Once restarted load up the same world that your old player seemed to be in and it turns back to your normal player and its like nothing got affected...
Also wherever you save the old player at it will be in that spot the next time it messes up and you join a realm or server again. Leading to believe there are two seperate player saves along with your world.

So, in conclusion there seems to be two player save datas that go along with your world when it is converted. But, the world data stays the same no matter what. And what triggers this is joining any realm or server. (Joining Xbox Live Multiplayer worlds do not affect this.) And the way to fix it is to just restart the game.

It would be great if this annoyance would be fixed (just dont remove the new, correct player data that corresponds with the world). At least it isn't as bad as I initially thought it was and there is no data loss.