Summary:

In creative mode, a player attempting to place a block by targeting a functional block (targeting which cannot be placed without sneaking) can create a phantom block. This happens when you simultaneously press the shift key and place the block (try to place it). In survival, the block appears for a second but immediately disappears (it does not disappear in the inventory).

Steps to reproduce:

1. Place a block targeting which you cannot place a block without a shift.
2. Try to place the block while looking at the placed block by pressing the Shift and the block placement key at the same time.
3. With your empty hand, try to "interact with the block" if the block is positioned.
4. Nothing happened?
   Break the block you placed and repeat steps 2 and 3.

Observed results:

Using the playback steps you will be able to create a phantom block. Also, if you used a block with a reaction (for example, a bell) for aiming, you will cause, at the same time as placing the "phantom" block, the reaction of the block you are aiming at (for example, ringing a bell).
It can disappear when trying to "interact" (button to place / use).

Expected results:

"Phantom" blocks should not be created. This can cause out of sync.

Video:

Creative

Minecraft 2021-08-31 13-41-43 (1).mp4

Minecraft 2021-08-31 13-41-43 (2).mp4

Minecraft 2021-08-31 13-43-06.mp4

Survival

Minecraft 2021-08-31 15-09-11.mp4