Expected Result
Scoreboard objective will tick up when placing single block
 
Actual Result
Only ticks up when placing from a stack of 2 or more blocks
 
Steps to Reproduce:
1. Create new scoreboard objective minecraft.used:

scoreboard objectives add test_used minecraft.used:minecraft.grass_block

2. Set display sidebar

scoreboard objectives setdisplay sidebar test_used

3. Add a stack of grass blocks in one slot, and a single grass block in another
4. Place single grass block (Notice test_used doesn't tick up)
5. Place grass block from stack of 2 more more blocks (notice test_used does tick up)

Notes:

This happens for all blocks within the game.

This even happens when trying to place a single block in creative!