It's been a long time.
I found out that some armor stands despawn like hostile mobs.
But some armor stands never despawn.
I tried to keep them by adding PersistenceRequired:1
but it doesn't work at all.
I do see some similar situations in Quick Search,
but it's far from 1.10 and isn't fixed.
So just a quick report to see if the developers
still know this issue.
Comments 3
summon ArmorStand 607.5 150 -0.5 {NoGravity:1,Invisible:1,Marker:1,Invulnerable:1,Tags:["fight18","core18"],PersistenceRequired:1,Passengers:[{id:FallingSand,Invulnerable:1,
NoGravity:1,Tags:["fight18","skin18"],Block:minecraft:diamond_block,Time:1},
{id:Guardian,PersistenceRequired:1,Invulnerable:1,Silent:1,DeathLootTable:"empty",Tags:["fight18","laser18","Invisible"]}]}
Basically, when the armor stand despawns, it leaves the falling sand visible.
Edit: idk what happened to the display of this command...
Please provide the exact command you're using.