When there's an stair facing down and you try to place another stair facing down adjacent to it, the stair is not placed or it gets placed in the wrong place.
This didn't happened to my friend who was playng in his PHONE
MCPE-30731
Stairs are getting placed in the wrong place when placed in stairs
Resolved
Works As Intended
0
Based on what I see in the video, this works as intended.
You placed the second block while your cursor was on a downward-facing surface. It is normal for Minecraft to interpret that as an attempt to place the new block below the block that was selected. If you are standing too close so that you occupy that block position, nothing will be placed.
Assuming your intention was to place the new block beside the existing one, you need to have the cursor on a sideways-facing surface instead, or on the wall behind it, depending on which direction you want to rotate the new block.