/Spreadplayers is off centered

When Using Spreadplayers, The Spread Area Is Off Centered From The Center Location.

Steps to Reproduce:

1. Create A Flat World With Upcoming Creator Features
1. Run /spreadplayers 0 0 0 4 @e[type=armor_stand] in a repeating command block
2. Spawn An Armor Stand

To Visualize Areas Spread To
1. Run /setblock 0 -50 0 diamond_block

4. Run /execute as @e[type=armor_stand] at @s run fill ~ -50 ~ ~ -50 ~ emerald_block 0 replace air in a repeating command block.

Observed Results:

Spreadplayers center is not centered

Expected Results:

Area Should Be Centered, By Spreading Out 4 Blocks From Selected Area

Screenshots/Videos:

Example On How Spreadplayers is Off centered