I reopened my Realm on a backup that hadn't corrupted yet, the corruption didn't occur again after that.
This bug is still occurring to me on the new 1.16 version. Playing on a realm on Windows 10.
Hi spud, thanks for investigating! Here is a folder containing both the bugged, and the backed up world (from the original bug report). Hopefully these can be of help to you!
https://drive.google.com/drive/folders/16oqfhomml4opVs_rCtk2B0Dg0wiB6E2P?usp=sharing
If the link ever somehow expires and you need the files again, let me know, I'll keep both world versions on my hard disk.
@MemoGoodNameYes I think what you're experiencing might be something different then. The world in which this bug occurred for me, was only created in 2019, only 6 months prior to me reporting this bug.