/give @s player_head{SkullOwner:"FaRo1"}/give @s player_head{SkullOwner:"FaRo1"}Result: A player head with this NBT:
{id:"minecraft:player_head",Count:1b,tag:{SkullOwner:"FaRo1"}}{id:"minecraft:player_head",Count:1b,tag:{SkullOwner:"FaRo1"}}On the next inventory update (moving an item, taking one onto the cursor and putting it back, picking up an item, …, but NOT /give-ing an item), the NBT changes to:
{id:"minecraft:player_head",Count:1b,tag:{SkullOwner:{Id:"46920312-c697-4a70-9e21-6d2db1122997",Properties:{textures:[{Value:"eyJ0aW1lc3RhbXAiOjE1NzE3NDc3MzQ0MzgsInByb2ZpbGVJZCI6IjQ2OTIwMzEyYzY5NzRhNzA5ZTIxNmQyZGIxMTIyOTk3IiwicHJvZmlsZU5hbWUiOiJGYVJvMSIsInRleHR1cmVzIjp7IlNLSU4iOnsidXJsIjoiaHR0cDovL3RleHR1cmVzLm1pbmVjcmFmdC5uZXQvdGV4dHVyZS9kZWE1Mzc0ZDlmOTY3ZmI3NzAwZDNiZjEwODVkM2VjMzNkOGQ5MGYwYzhlNDAwYzJlZmJlNTczM2QyNWMzZTZmIn19fQ=="}]},Name:"FaRo1"}}}{id:"minecraft:player_head",Count:1b,tag:{SkullOwner:{Id:"46920312-c697-4a70-9e21-6d2db1122997",Properties:{textures:[{Value:"eyJ0aW1lc3RhbXAiOjE1NzE3NDc3MzQ0MzgsInByb2ZpbGVJZCI6IjQ2OTIwMzEyYzY5NzRhNzA5ZTIxNmQyZGIxMTIyOTk3IiwicHJvZmlsZU5hbWUiOiJGYVJvMSIsInRleHR1cmVzIjp7IlNLSU4iOnsidXJsIjoiaHR0cDovL3RleHR1cmVzLm1pbmVjcmFmdC5uZXQvdGV4dHVyZS9kZWE1Mzc0ZDlmOTY3ZmI3NzAwZDNiZjEwODVkM2VjMzNkOGQ5MGYwYzhlNDAwYzJlZmJlNTczM2QyNWMzZTZmIn19fQ=="}]},Name:"FaRo1"}}}This can have weird effects, for example giving another head with the same command creates a new stack whenever an inventory update occurred in the meantime. And commands expecting a "Properties", "textures" or "Value" tag to be present would fail at first. It's also inconsistent that the /give command does not cause the NBT change.
Linked issues
duplicates 1
Comments 2
Duplicate of MC-80025.
I was only able to reproduce this by moving the player head in creative mode.
Other inventory updates did not seem to have that effect.