execute if/unless doesn't work separately for each target

Steps to reproduce.

1. Put 2 Armor Stands on ground, and make one of them into any block that is not air using /setblock.
2. Run this command:/execute as @e[type=armor_stand] at @s unless block ~ ~ ~ air run say @s
3. then you find no output on chat screen.

What I expect is the one IN block would give output, and the other would not. Conditions should be separated for each target that runs this command.