klaus knechtel

I found a solution for my experience with this bug. I had to go to  the following path:

...AppData\Local\Packages\Microsoft.MinecraftUWP_[ID String]\LocalState\games\com.mojang\resource_packs

and delete any folders with (1) in the folder name, and one folder representing a pack that wouldn't even show up in the list of options when I opened My Packs while in a realm. Once I relaunched a couple times suddenly I had access to My Packs again. Hope this helps! 

I'm assuming that one was causing the primary issue, and had a bad .JSON like @Mike Shultz proposed.

https://drive.google.com/drive/folders/1plB3FjuT22moAmYwl3FpTIteYw8lS1p_?usp=sharing

This link is to a folder that contains the WIN10 exports of my realms world saved before 1.18 update, and after (Both mcworlds are well over 50mb), as well as a screenshot with the coordinates I was at when I discovered this bug.
I agree with others that this was probably just an artefact from the world conversion, and it's not like it's an issue per se. Just kinda neat and a probably good indicator of what kind of weirdness can occur when you run world generation again on already loaded chunks.