If you start up the Minecraft server and use the /give command to get a player head, it will only ever have the skin you had applied when you first joined the server. Restarting the server will refresh the skin to your latest/current one.
Steps to Reproduce:
Join a server
Use the following command:
/give @p minecraft:player_head[minecraft:profile=*[YOUR_USERNAME]*]
Change your skin
Rejoin the server
→ ✔ Your player skin is different.Repeat step 2
Expected:
The player head would be of your current skin, and not an outdated one.
Observed:
The texture of the head will be of an outdated skin.
I think this was fixed in 25w34a not sure though