Custom player heads are called block.minecraft.player_headnamed.
/give @s player_head{SkullOwner:"Dinnerbone"}
→ It's named "block.minecraft.player_headnamed" rather than "Dinnerbone's Head"
MC-122810 Delivery of the head in minecraft, it has a strange name.
MC-122650 Player heads aren't affected by upgrade paths, renamed to "block.minecraft.player_headnamed" + head texture does not show, only when placed