Log out chunk changing biome colour

Relogged into a survival world in a warm ocean biome and the chunk I logged out in changed the biome colour theme to a different ocean biome,

To recreate:
1) Log out of singleplayer Minecraft in a warm ocean biome
2) Re log into the same world and the chunk you logged out in will be a different colour

I tried relogging into the same world and the issue fixed as if it was never there. I do have screenshots of the issue though (first 2 images). The last 2 are after attempting to recreate the bug but the chunk now has the correct colours