I added a screenshot of an entire ship being placed in some already generated chunks, i also had half of an amythest Geode generate in an underground base but it seems to have vanished. This is in addition to the water and lava being generated when chunks are loaded. Given that all of these are features it stands to reason that the issue is features being generated again despite chunks having already been generated.
Im experiencing it on BDS as well in 1.17.40, with CnC experiment on.
I am experiencing this on BDS 1.18.30.4
I get the outside of world error when attempting to fill blocks outside of the simulation distance, but inside the render distance.
Not sure if this is the same issue or a different one and the reporter here just used simulation distance and render distance interchangeably. It seemed better to leave a comment then opening a new issue that would probably be marked as duplicate.