I have a font with a subset (ss01). Now I want to make a ligature for a.ss01 followed by another a.ss01. I made a glyphs named a.ss01_a.ss01. In the dlig feature the rule is automatically generated:
sub a.ss01 a.ss01 by a.ss01_a.ss01;
But in InDesign (with otf-font installed in the Font map of Adobe InDesign) the two characters aren’t replaced by the ligature when I check ‘Stylistic Set 1’ and ‘Discretionary Ligatures’.
I tried if it helped when I renamed the ligature to a_a.ss01 and renamed the feature to
sub a.ss01 a.ss01 by a_a.ss01;
but that didn’t solve the problem.
The strange thing is that the feature worked well a year ago when I made a first version of this font with an earlier version of GlyphsApp. Do you have any idea how I can solve the problem?