At the exit of the minecart, I'm supposed to go out on one side of the minecart. From layer 65 and up, I'm in the block below the minecart, I go in the block where is the rail and the minecart.

I normally go out on a four block around the minecart. As below the 64 layer.

On the images, in blue where the problem does not appear and in red where it occurs.