Android Marshmallow Nexus 5 video ad orientation problem

My app is portrait oriented only and uses UnityAds via Fyber. I test it on Nexus 5 with Android 6.0.
Video ad played correctly, but when it has finished I got this:


I enable the option to "change video orientation according to device" as was written in the thread http://forum.unity3d.com/threads/ads-in-portrait-mode.285579/
But it does not resolve my problem if I rotate device to watch video in landscape mode.






If I tap anywhere on screen activity start showing correctly

So it works fine only in portrait mode as my app is portrait-only.
I did not receive this on any other device.

Any suggestions will be appreciated