Since iOS10, there seems to be a problem with the CSS border-image attributes.
I used to work with something like this:
border-image: url('data:image/png;base64,somedata') 30 30 30 stretch;
However, since updating to iOS10 on iPad (and I would guess on iPhone as well), the border-image is no longer visible, leaving it transparent.
This happens with Safari and Chrome browsers on iPad.
Here's a fiddle so you can see how it behaves on iPad vs computer: https://jsfiddle.net/g99y6pg3/1/
I also tried with a border-image: url(filename.png) instead of data:image/png, but got the same result.
Thanks for your help!
You need set property 'border-color' = 'white'