You cannot place blocks when facing negtive or positive X axis and a full block is in front of you.But you can place blocks when facing negtive or positive Y axis.

Steps to reproduce:

1.place a full block on the ground.  

2.sprint to the block from the negtive or positive x axis direction and make sure you are very close to the block.

3.try to place another block on it.

Expected results:

the block is placed.

Observed results:

the block can't be placed.