I had a funky experience with opentype the other day (not entirely relevant, but maybe!) where I was trying to insert a apostrophe into a well known brands typeface, everything in the tables was jiggy, but in applications, no apostrophe!
Turns out the problem was (quite obvious really) that the cells for single quote, apostrophe, quote mark all require an entry for the application to use the correct glyph according to context. So my apostrophe required entries at 2018, 2019 & 0027.
Maybe a similar problem to yours. Maybe.
Peace!