sass vs node-sass visual difference

[stickfigure]

rmd 2.4.3, chrome 86.

Exact same code, the only difference is replacing node-sass with sass+fibers in the package.json.

The node-sass version of a menu, with spacing between text and icon:

https://monosnap.com/file/2CeDgaOLTNthsTUeof3M0INGeafvcq

The sass version seem to be missing the spacing:

https://monosnap.com/file/GkjQlIrur72aFHWYVfgEONFIKJCO3T

This seems to work in one place but not the other:

.rmd-icon--before {
    margin-right: var(--rmd-icon-text-spacing, 0.5rem);
}

[mlaursen]

Darn.. This probably means sass doesn't like this mixin if all the other text icon spacing works. Wonder if there's a difference in how strings/escaping between the two.