Missing outline size in SCSS minify with @media and var

[renebuehling]

Hello,
I got some weird behaviour that I don't understand:

test.scss

@media screen 
{
  :root {--select-color:blue;}
  .selected {outline: 1px solid var(--select-color);}
}

compiles into test.css ✔

@media screen {
  :root {
    --select-color:blue;
  }

  .selected {
    outline: 1px solid var(--select-color);
  }
}

and minifies into test.min.css ❌

@media screen{:root{--select-color:blue}.selected{outline:solid var(--select-color)}}

In the minified version 1px is missing in outline's styling. This seems to happen only under certain conditions, i.e. for outline, but not for border and only when @media and var() are involved...?

Thank you for any help!

Version: 6.8.122 of Formatter Hero - Beautify Sass/Less/Scss/Typescript/Javascript/Jade/Pug