Generate a new world using datapack, set its "min_y" = -1024, and its "max_height" = 3056(the datapack which I'm using is provided).

Generating settings which I use:
Game Mode - Creative
Difficulty - Hard
(Others are default setting)

After world loaded, using command:

/setblock ~ 1023 ~ minecraft:stone

or

/fill ~ 1023 ~ ~ 1023 ~ minecraft:stone

they worked correctly.
However, when execute command

/setblock ~ 1024 ~ minecraft:stone

or

/fill ~ 1024 ~ ~ 1024 ~ minecraft:stone

they don't work.
For "setblock", it says: "Could not set the block", and for "fill", it says: "No blocks were filled".
Even using command

/fill ~ 1023 ~ ~ 1024 ~ minecraft:stone

 to fill blocks, it only apply on the lower block, and make the higher block a ghost block.
In other situation, if the Y value are higher(I tested Y=1536), the error message will become "An unexpected error occurred trying to execute that command", but if you run command on coordinate which had executed by two types of commands, the error message will become the string I mentioned above.