Workaround that works for me, leave the world and rejoin and you should be back where you were originally.
The bug still occurs in 1.19.40. Deleted chunks near my spawn and reset others to different biomes. Nothing was destroyed and am able to import the chunks form old backups. This should be fixed
It appears that this issue has been fixed in the latest bedrock update.
This is a Java-only Feature.
Possible Cause and Fix Found (for PC)
My computer had faulty memory when the corruption occurred (failed memtest64 with over 50k errors). Replacing it seemed to have fixed this issue as i have experienced no new world corruption in any of my worlds. You can check for this yourself by running Windows Memory Diagnostic. If the test detects hardware issues then you might need to buy new memory (RAM) or contact the manufacturer for a warranty claim.
I don't know any possible fixes on consoles or mobile devices since their memory cannot be altered