The bug
Marker armor stands cannot find themselves when a value of 0 is used as distance selector argument value.
How to reproduce
Summon a non-marker armor stand
/summon armor_stand ~ ~ ~ {Tags:["non_marker"]}Have the armor stand use a
distance=0selector/execute as @e[type=armor_stand,tag=non_marker] at @s run say @s[distance=0]Summon a marker armor stand
/summon armor_stand ~ ~ ~ {Marker:1b,Tags:["marker"]}✔ The armor stand finds itself as expected
Have the armor stand use a
distance=0selector/execute as @e[type=armor_stand,tag=marker] at @s run say @s[distance=0]❌ The armor stand does not find itself
This is not a duplicate of MC-88533 because this also affects area_effect_clouds!
Summon an aec
Print all entities that are not within radius 0 of themselfs: