If I set the block's x coordinate to anything that's out of the area of the block by about 2 blocks, the hitbox shrinks. If it goes far enough, the x hitbox is disabled entirely. What's weird is that this seemingly only happens with x block coordinates, and not y coordinates.
Block collision is internally sorted by the game to improve collision check performance. If you want to move a block programmatically, use the block:translate(dx, dy) method