Hello, 

I just found a bug concerning minecraft skulls.

First, let's say I give myself a player head like so :

       /give @p minecraft:player_head{SkullOwner:{Name:"Jeuns2France"}} 1

Now if I sneak+pickblock, I just get a regular steve head and that was not the case back in  1.15.2, also the skull doesn't get any texture (even though its says (+NBT ) ! ) 

There's also the "Custom Texture" case :

/give @p minecraft:player_head{display:{Name:"{\"text\":\"Diamond Block\"}"},SkullOwner:{Id:"476291e8-56c7-4ce0-ae0c-ec5bef7d3f5f",Properties:{textures:[{Value:"eyJ0ZXh0dXJlcyI6eyJTS0lOIjp7InVybCI6Imh0dHA6Ly90ZXh0dXJlcy5taW5lY3JhZnQubmV0L3RleHR1cmUvMzAzNTAwZGQwOWI0NTRlYWI5ZjdkZTgzM2RiMTg4YTJmNjVlNWZjZWRmMTI4YWU1MWZmMjgwN2YzZGUyYWVkOCJ9fX0="}]}}} 1

With this method, the head now has a texture BUT i place it somewhere then sneak+pickblock  it gives me a regular steve head  (even though its says (+NBT ) ! )

Thank you for reading, 

best regards