When attempting to upload a World to a Realm, It appears to completely finish loading under "Export in Progress" and even pops up and says "Level export finished successfully", but then gets stuck on "Initializing Upload" and doesn't load any in the progress bar and then eventually says "ERROR: An error occurred" I've repeated this process over 10 times and cannot get this to work. This error message is also frustrating because it didn't tell me what went wrong?

We would also lose items on survival during this process, although I reported that in: REALMS-8905

(Note: I assume this has something to do with file size, but this makes it hard to continuing playing on the same world using Minecraft Realms for even a couple of months, because this world is approx. 300MB in size and was generated in late July 2021)