You can phase through placed blocks

[Sea L King]

Steam or GOG

Steam

Single Player/Multiplayer

Both

Operating System

Windows 10

Terraria Version

1.4.4.9

Controls Used

Keyboard/Mouse

when placing a block to the right of the character and standing right by it, breaking it and then move the tiniest bit right, you can place a block where it should be obstructed by your character, and phase through it. Doesn't work when going towards left side.
I would attach a video but it said wrong format

 

[adjacent]

You've discovered Hoiks! This is technically a bug but the developers like it so much they have made it a feature! They can be used to mainly travel across the world at the fastest speeds possible but my favorite use for them is to cheese the Dungeon and Lhizard Temple.

 

[punchready]

This specific case is not technically hoiking, beyond the fact that the character is inside solid blocks in both cases, especially considering it only works on the right side.
Hoiking is more about stairs making players not collide with solid blocks anymore and the code for pushing the player out of a solid block working in such a way that sloped blocks move the player very quickly.

Regarding this specific inaccuracy, IIRC getting the correct tile collision area when placing something is mildly annoying so this may not be worth fixing.

 

[Sea L King]

What I found out also is that you can interact with chests, go a pixel or two to the left and still be in the chest but out of reach to click out of it through the chest itself