The fix of MC-2404 has led to players not being able to step down a block while sneaking with a block above the head.
You now need to mine the two blocks above, and to the side of the player to jump a full block up and then fall two, onto the block you wanted to get to.

This is really only important for multiplayer, but there a very significant problem. Because when trying to hide or get past someone without being seen underground, you have to usually not only dig horizontal tunnels. And when making underground stairs up, you would have to make them 3 blocks high to get down again, instead of only 2 blocks. That's 50% more blocks to break to make a flight of stairs, and in my opinion quite significant.

It probably conflicts with the fix of MC-2404  entirely and will therefore probably from now on be seen as intended behaviour, I just wanted to ask for confirmation of this, or if it were even possible to fix both.