Why did AVPlayer stop working in iOS 9?

Question

iOS

In iOS 8, there was a simple application with playing audio streams through AVPlayer and it coped with its functions without any problems.
In iOS 9, some devices also play streams without any problems (including in the emulator). Another part of iOS 9 devices for some reason only plays streams if headphones are connected (silent mode is not set). How can this be?
I added the following lines to the info.plist file, which did NOT solve the problem:

<key>NSAppTransportSecurity</key>
<dict>
    <key>NSAllowsArbitraryLoads</key>
    <true/>
</dict>

Why do several similar devices with the same iOS 9 operating system behave differently? How to solve the problem?