Make sure you export without hinting and have all hints deleted in the font.
How do you pick the ligature? From the blue ribbon or by activating discretionary ligatures in the palette menu? Does it make a difference, I mean how you trigger the ligature?
@mekkablue I tried both methods to pick the lig, the result was the same either way. the only thing I haven’t tried here is to delete hinting; will do later today. (edit: I am also using the Adobe fonts folder.)
@GeorgSeifert UPM is pretty high; set to 4000 to make all those delicate curves. will send the glyphs file in a moment.
(sorry for such an open-ended question; I wasn’t really sure where to start with this one since there are so many possible points of failure. )
Adobe apps have Problems with coordinates bigger than a certain value. I had distortions above 4000 units. To see if that is causing this, scale the outline in that ligature to be less than 4000 units.
(I started this piece very large and without fractional coordinates to leave open the possibility for it to become variable ttf for whatever reason, but I don’t think it’s going to need to happen. I’m still a little mentally stuck in that set of conditions.)