Ok, thank you for your reply, I will test it under vanilla environment as well as modified environment (with customskinloader) afterwards.
Thank you for your generous assistence! I succeeded in circumventing the issue by switch to different gamemode then switch back. I cannot properly switch to survival, as flying won't be forbidden during survival gamemode, but it doesn't really matter, as this world is for pure creation previously. I've installed BetterRTX on my labtop in order to make use of ray tracing, which may be the cause of my issue I guess.
I've changed the permissions. It's public now.
Thank you for your reply @katzdy, my Minecraft version is 1.21.1 with the following mods: fabric & fabric-api-0.102.1+1.21.1, iris-1.7.3+mc1.21(flagged as compatible with 1.21.1 on CurseForge), sodium-fabric-0.5.11+mc1.21.jar. As CustomSkinLoader's 1.21.1 compatible version gets released, I will give it a try.
感谢回复@katzdy, 我的minecraft版本是1.21.1,模组我只用了fabric & fabric-api-0.102.1+1.21.1, iris-1.7.3+mc1.21(Iris CursorForge主页上显示兼容1.21.1), sodium-fabric-0.5.11+mc1.21。等到兼容1.21.1的CustomSkinLoader版本放出后我试试看能不能解决问题