If I hold right click on a furnace minecart in the new snepshot it makes it move in the direction I'm facing, and I'm not holding coal or any smeltable item.
If I hold right click on a furnace minecart in the new snepshot it makes it move in the direction I'm facing, and I'm not holding coal or any smeltable item.
This is intended behavior for furnace minecarts (yes, there actually is behavior for them that works correctly!). This behavior also works in 1.12.2.
You can right-click it to apply a very small boost, which can be used to change the direction, or shove two minecarts together to force a link (yes, that's a thing; no, it doesn't work very well). The boost only applies a small push; it does not actually give the cart any fuel.