When the world file running in the dedicated server reaches somewhere between 7-10 GB, when you run the save hold, and save resume, and save query commands, newly generated chunks to not save properly, (pre generated chunks save just fine) Some chunks just delete leaving a 16 by 16 hole in the ground going to the void, and sometimes this happens to large areas of new chunks, which have deleted entire bases built on my server. After a while, all the chunks will  just reset as if you where generating them for the first time.

what I expected was 

running the save commands would save the world, including newly generated chunks.

what actually happened was

pre generated chunks saved like they are supposed to, but newly generated chunks failed to save properly, causing chunk errors, and eventually the server resetting the chunks completely.

How to reproduce

run a world file of 10 GB in size on the Dedicated Bedrock Server

Teleport out to where new chunks would generate

Make a few edits, break a few blocks, place some blocks

Leave the server and, on the server console, run the save hold, save query, and save resume commands

then join the server and the corrupted chunks should be close by