Font turns to white blocks

Hello!
On some android devices a font turns to white blocks.

I tried a lot of things: first all my fonts were "otf", I changed them to 'ttf" and the problem disappeared. But now it is here again. In the screenshot "Let's find out..." phrase is a font where I simply changed ".otf" to ".ttf". But other white squares are fully converted ".ttf" font. But also numbers in upper corners are fully converted ".ttf", too. And they look normal.

P.S. on iOS it works correctly. And forgive me my English, I'm not a native speaker.

 

Same issue

 

Did you work out what the problem was? We've just launched our game live, and users are reporting this issue, which means our game is unplayable on some devices (Android only)

 

May be this fond doesn't exist on those devices. What font are you using?

 

It's an otf font, it's included in the assets directory, so should show up on any device.

 

Is this issue solved?