When a negative coordinate is used in a /setblock command the block will be placed one block in front of where it should be. For example, if I enter /setblock -12 100 -12 stone, a block of stone will be placed at -11 100 -11. I know this is an issue previously mentioned but that was back in the snapshot for 1.13.0 and the issue was marked as resolved without being fixed. This is especially frustrating as it has broken three systems in my world.