My font, a connected blackletter, has a complex system of features which seem to mess up MS Word 2016 on Windows 10. It uses, among others, the ss01-..., liga and dlig features. I can switch liga and dlig on and off without problem but only until I start setting different options for subsections of my text.
For instance, if I set all ligatures on for all the text, and then try downgrading a section of the text to only standard or only discretionary ligatures, the setting takes no effect... in the main view; however, if I go to the stylistic sets menu, the correct and expected version of the selected text (regarding the active ligature setting) is displayed in the stylistic sets previews. Moreover, if I turn on any of the available stylistic sets, the previews come alive and I regain control over ligatures in the main view as well. If I ever switch back to default style the ligatures go back to an undefined state in terms of display. It seems like something is blocking the ligatures from being displayed accordingly to the settings.
If I clear formatting and reformat the text, I can again set ligatures on and off, but the whole thing seems to get ruined once I change options for one selection and then for another, neighbouring one. Sometimes changing the options takes effect, but affects also a following section of the text, for example the next word. And the substitution rules are most likely not dependent on it. If I select the errouneously affected word and check its settings they are unchanged and so is its preview in the stylistic sets panel.
Any ideas? Other than dump this poor piece of software?