End upgrading badly from 1.18.2
When upgrading any 1.18.2 world to 1.19 the end generates with weird chunk borders likely caused by the world blending. Since I created this world just to check if it wasn't a modded issue i can confirm this was done 100% vanilla
To recreate:
make a new world in 1.18.2
Go to the end and fly to theĀ outer islands or /kill the dragon and go through the portal
Fly around a bit to load chunks
Quit Minecraft and start Minecraft in 1.19
Go to where the world would upgrade terrain (generate new chunks)