Loading Older Saves on Startup

Hello. Most of the time when I login and start my game, I don't have too many problems. But every now and then I'll notice it load me from a very old part of my game; (back when I used to play it on xbox 360 and transferred it to xbox one, and now to the bedrock). When that happens, I'm afraid that it'll erase all my work that I've done, so I do a Hard Reset on my xbox one. When I turn it back on, it loads me back at where I normally left off. Every time though, I would always have the same thumbnail screenshot in my Game Select screen. Today, however, it loaded up a previous save from a few days/weeks ago for the thumbnail, but it loaded me normally.

And earlier this week, it loaded me about 50 blocks above where I last stood, with no way down. I feel like it's mixing up saves badly. I'm scared of logging in and suddenly falling out of the sky.

Thank you for your time.