In the latest beta 1.3.26 (530) I’m occasionally seeing curves flatten out–the off-curve points disappear on random segments of letters. Oddly, even though the segment displays (and exports) as flat with no off-curve points, if I use Tab to step through all the points, I’ll have to hit Tab three times to get through this segment, as if the tab is stepping through the missing handles. (Likewise, I can’t Option-click on the segment to create handles, like I can with truly straight segments.)
This seems to happen to recently edited glyphs, I think when saving and/or exporting.
I think I have fixed that already.