The texture for the shortcut button in the skin customization screen can't be changed with a resource pack, even on cold boot, despite RP texture the exact same identifier to the one in the release jar.

can you send the relevant logs?

I tried it myself and it worked just fine. Can you also send me the resource pack you are using so I can verify?

Oddly, it started working fine, just randomly. I've done nothing except replace Canvas with Sodium but that's irrelevant, isn't it? I couldn't replicate it reloading the resource pack through the menu and in-game with F3+T. Perhaps this issue should be closed as invalid?

Tested with Canvas and it still worked