I have been building my city world since 2014 on the PS3, but for whatever reason, the first chunk south west of the center of the world (0, 0, 0 heading negative X and towards the evening sunset direction) are reverted back to stuff I had back in 2015. The same thing happens to a chunk next to the map border on the east side of the map (within the legacy's central map). Once again, 2019 world meets the 2015 chunks once again (I'm just glad the rest of it doesn't look like 2015- that year was terrible looking in hindsight.)

I keep several copies of my world in case of a bug like this, and I've tried using a 2018 copy, a recent 2019 copy, and the current copy of the legacy-based world as the world to convert.

I've also tried editing the newest copy on the legacy mode, and the blocks that I placed right in front of myself didn't convert at all- when the world was converted during this attempt, I was sitting in a chunk with this issue. Another thing I tried doing: sitting next to the point of failure but not in the chunk itself, but there's no difference- it's always the same 2 chunks.

Lastly, I've removed all copies of my world from the PS4 so the system isn't trying to pull data from anywhere but the world I want to convert since I did have a 2015 copy on my PS4 at the time of discovering this issue. No difference still.

I'm hoping a patch will come out before I get too far into developing the future of my world on Bedrock Edition. My world's been through a lot of bug-filled updates over the years, even those infamous memory leaks that 2015 was full of, and I look forward to this being fixed