Section Import makes all chest/shulkers/barrels empty and shulkers+chests are invisible

[ctom4242]

I'm attempting to upgrade my world from 1.18 to 1.19. In 1.19 world generation on my world's seed there are two Ancient cities directly below my base. I generated new region files for the area and have been attempting to merge them with the old region files.

I have been following this guide, specifically the section for Partially Importing Chunks.

I have tried the import both ways, merging the new into the old and vice versa. I thought their might be some file version mismatch so I imported the 1.18 region files into a local world in 1.19 and then later used that same world to generate the new region files. The result was no different.

EDIT: I have also tried the "optimize world" function on both sets of region files, the result was no different.

[ctom4242]

I also want to add that signs and player heads were likewise made invisible. The player heads have all reverted to Steve heads

[ctom4242]

Ok so I have been playing in the messed up chunks, I was just going to fix everything that was broken (I moved all my storage into the nether in advance), but now I've come to a real head scratcher. It's raining inside all my buildings. Rain is not passing through any of the natural terrain (which existed in the new region files my old chunks were merged into) but any of my placed blocks from the old region files are transparent to rain.

[HoldYourWaffle]

I'm not an expert on minecraft weather, but this sounds like the chunks' heightmaps are broken. Maybe deleting them will force the game to recalculate them?