In my settings.json I have the following lines.
"editor.fontFamily": "'Fira Code SemiBold'",
"editor.fontLigatures": "'cv24', 'cv31', 'zero', 'ss02', 'ss04', 'ss05', 'ss09', 'calt', 'liga'",
All of the Stylistic Settings I have tried work except for cv24 and cv31 which are supposed to make /= look like ≠, and make the parentheses rounder according to the Fira Code github. Does anyone know how to get these ligatures displaying correctly?
From reading about similar problems (e.g. here and here) I have added 'calt' to the list of settings, and I do not have "editor.letterSpacing" enabled. I also made sure I didn't have an old version of fira installed as mentioned here.