This is a repost of MC-1307 for Bedrock Minecraft.

The glitch

Stairs always keep the same hitbox even when being attached to the outside or inside of a corner. For inside corner stairs, there will be a gap in its hitbox, allowing players to interact with the world and projectiles to fly through the stair's model box. For outside corner stairs, there will be an extra hitbox, denying players from interacting with the world and projectiles from flying next to the block.

Steps to Reproduce (inside corner stair)

1. Place a stair (this is stair A)
2. Walk to the space just left of stair A
3. While not moving, place another stair on the opposite side of stair A (this is stair B)
4. Walk behind stair A and stop before going past stair B
5. Break the block directly beneath you
6. Aim at the top right corner of stair B

Here, the player cannot interact with the block. Shooting an arrow in this state will make the arrow go through the stair model.

Steps to Reproduce (outside corner stair)

1. Place a stair (this is stair A)
2. Walk to the space just right of stair A
3. Face towards stair A
4. Look down, jump, and place another stair (this is stair B)
5. Walk backwards 1 block and break the block beneath you
6. Aim above the left side of stair B's model

Here, the player can interact with the block. Shooting an arrow in this state will make the arrow stop in the air.

Original Description

So I've notice if you look through the empty parts of stairs there's no hit box for the stairs so you can click a chest or a whatever. But on the stairs that wrap around a corner only one side has no hit box and the other does. I've left some pictures where you can see the hit box of the stairs on one side and another where I'm selecting the chest.

Video Example

https://youtu.be/NiHMKR3WF84