Under @nakahide3200's adivce, I found it was the allanoricil.nuxt-vscode-extension-0.0.21 extension that caused this problem.

here is how I found it:

$ cd \~/.vscode/extensions

$ ls | grep nuxt

allanoricil.nuxt-vscode-extension-0.0.21

$ rm -rf allanoricil.nuxt-vscode-extension-0.0.21

Thank you @nakahide3200 very much!