So I’ve been experimenting with various features & settings and came across this:
I know I’m probably doing sth wrong, but is there a reason why 2nd, 3rd, and 4th i’s are also shifted down, then 5th is level, and 6th is back up again? Without the 2nd kerning pair, all is level:
Sorry to bother y’all, but I’m trying to understand the mechanism.
That looks strange to me as well. Maybe our layout engine is failing here, so do send us the font project file and we’ll look into it.
I have looked into the issue and I think it might be due to a shaping engine timeout, as it takes too long to render it all.
Does it work as expected if you use a shorter text string for the preview?
Actually, it works with the long text I sent you just fine when I delete the 2nd kerning pair from the list:
But it doesn’t work with any text length with the 2nd kerning pair on the list:
{Kerning1 (kern) > PairAdjustment1_1 (2/2)}
Oops, I was testing with the Latin script selected. Now I see what you mean.
FontCreator seems to align something vertically. We will look into it later this week.
In Word and in a web browser the kerning isn’t working at all, unless you explicitly set the OT Class of overlinecomb to Base. But then you get different results, so maybe you are pushing the limits 
OK, thanks for letting me know. 
The latest unofficial update we released earlier today also fixes this issue, but the change might have broken other features, so let us know if it all seems to work as expected.
Thank you, will do.