Oups, sorry, I did not realize you posted an answer.
I had this kind of problem on build 10512 but this was a system related problem: at a point, i was unable to send and receive SMS.
I used the CMJ1 ROM. You have to use this one in order to get the latest Samsung firmware (15.3.2). You can find it in
grozaman's Yandex drive.
By the way, I'm now on the 10572 build and it is kind of amazing. It runs great on the Ativ S. They improved the battery usage, camera pictures are no longer blurry, notifications for the message/phone are back when the screen is locked, no more flickering tiles when you go back to the home screen, less error with missing applications after a hard reset (the first hard reset worked perfectly for me)...