The bug

When opening the social interactions menu, if you are in spectator mode, your skin will not update. It will be shown as a default skin.

How to reproduce

1. Join a world in first person view
2. Go into spectator mode using the command /gamemode spectator
3. Exit and rejoin the world
4. Open the world to LAN
5. Open the social interactions screen
6. Notice how the skin appears to be a default skin
7. Change the tab to 'Hidden' and back to 'All'
8. Notice how the skin updates