My account is glitched on Launcher

(Sorry for my poor english.I'm Chinese.)

I usually do not use offical launcher to launch my games(usually the third party laucher called "Plain Minecraft Launcher").

But today when I tried to log into a server,It shows"Failed to log in:null"

I'm confused with this message and I decied to open Minecraft Offical Launcher.When I tried to check my skin,it shows"pick your own Mineraft profile name. It only takes a minute!"

Totally shocked in my mind.I used the ID "Crystalaura_uwu" since 6/11/2022.with the own bedrock to own java edition.

But when I logged minecraft.net,It's normal and my profile name is still there.Nothing changed in minecraft.net but on launcher.