Syntax highlighting was broken with lang="less"

[jaye2fung]

Notice the screenshot here, syntax highlighting is normal. But when I added lang="less" , the syntax highlighting disappeared. It's in a .vue file.

Normal without lang="less" in a .vue file.

Not normal with lang="less" in a .vue file.

[Groupguanfang]

Same question

[Amparose]

This is frustrating as it breaks code completion as well.