Player heads do not glow in most situations. I have tested this with item frames, item displays, and armor stands. Interestingly, player heads do glow in the head slot of the armor stand, but not in either hand. The armor stand and item frame do not have to be invisible, this is only to make the issue easier to notice. This was not the case in previous snapshots or releases.
This command can summon an armor stand holding an iron block in one hand and a player head in the other, for easy replication of the issue:
/summon armor_stand ~ ~ ~ {Glowing:1b,ShowArms:1b,Invisible:1b,equipment:{mainhand:{id:"minecraft:player_head",count:1},offhand:{id:"minecraft:iron_block",count:1}}}
Environment
Windows 11 Laptop
Wrong video lol