sounds like an issue with ios 9 more than the game itself... why don't you just switch the fonts globally in your settings if you aren't happy with them? I've had that ability for years on my android devices.
Players who recently upgraded their Apple devices to iOS9 have been experiencing font issues with overlapping text or special characters appearing incorrect. This is a known issue caused by the OS update, and we are currently working on a fix.
(I believe what happened is that the default font changed in iOS9 :/)
Gambrinus.... U cannot change fonts in ios...
It seems that nexon did not check this issue in ios9 betas... And now they need to make a fix under pressure...
seem like an ios9 issue to me... I've never had that kind of issue when my os upgrades. maybe you should try using devices that don't break apps when the upgrade.