Tranparent textures not showing in device ( IPHONE 5)

To experienced with mobile development …
I have a transparency problem in IOS. Considering a PNG texture with transparency, it will appear OK in the editor and in mobile preview, but not in the iPhone ( 5 ) . The texture is showed like just a opaque plan. I tried with various textures and various locations ( UMG , planes , particles ) , and both 4.8.3 and in 4.9 and compiling with both PC and MAC . The strange thing is that the Android shows transparency of the texture OK , the problem only occurs in IOS.
Thank you in advance for any help.

Hey Rudse,

Could you please provide me with a link to the PNG that you’re using on your project? If you’d like it to stay out of public view, please submit it to me through PM. Also, what version of iOS are you on?

Thank you!