Why this is a problem:
Invisible armor stands with custom names are often used as signage. When such an armor stand is in front of a chest or button the player is unable to click on the chest or button if the armor stand is directly between the player and what they are attempting to interact with.
Additionally you cannot place blocks "through" an inviz armor stand - annoying for map creators.
Repro steps:
Place a chest
Summon an invisible armor stand (command below)
back up 2-ish blocks and attempt to open the chest
If you're able to open the chest move around a bit and click around, you'll find the dead spots
Command to summon invisible armor stand:
/summon minecraft:armor_stand ~ ~ ~ {NoGravity:1b,Invulnerable:1b,Invisible:1b,Small:1b,NoBasePlate:1b,CustomNameVisible:1b,CustomName:"{\"color\":\"red\",\"text\":\"Bug Report\"}"}
Use
Marker:1b
to disable the hitbox.