Ligatures are disabled in CSS for elements where our Space mono font is currently used in tlwebadm and tlwebaccess. See bug 8166.
There is a risk that the ligature property set for elements that use Space mono accidentally gets inherited by elements where other fonts should be used with the ligature property enabled.
Ex, doing the following (with our CSS-files):
This results in a textarea where the font is set to Mulish, and ligatures turned off. Where the expectation would be to have ligatures enabled, since the font-family is not set to Space-mono.
We could fix this by for example disabling ligatures for the font itself.