The loaded classic skin becomes the initial skin in multiplayer

Hello, I'm using a translation site, so I'm sorry if there are any mistakes.

When I set an original skin as a classic skin and played multiplayer, it ended up being the default skin (Steve, Alex, etc.). (Photos 1 and 2)

My screen is set correctly. (Photos 3 and 4)

The item "Allow only trusted skins" in the setting screen is also turned off.

Also, the skin created by the character creator was also an initial skin.

I want to solve it somehow. Thank you.