Unity 5 keyboard bug

unity version: unity 5.1.2f
platform: ios

i create a demo and only add a InputField in my scene

my operations like this:

firt situation:
1: i’m running my demo on ipad and clicking the input field, the keyboard push out automatically

2: press home button, then back to my demo. the keyboard was visiable but it can not work

second situation:
1:i’m running my demo on ipad

2: press home button, then back to my demo.

3: click the input field, however the keyboard not appear, and it can press the keyboard’s buttons

is there someone have met the same problem? and how to solve it?

Reading through the forums, input fields are completely broken on Android and iOS since the 4.6. I posted a bug about a month ago but still no response. The problem appears to be with the static keyboard and race conditions with releasing your finger before the keyboard has fully disappeared and reappeared.