YouTube volume is very low when played during a WebRTC session

I am working on an iOS app with WebRTC. During the chat, volume is fine. But if I play an embedded youtube video through WKYTPlayerView, volume of the video is very low. If I disconnect the chat, video volume becomes normal again.

I have tried several things and I have been looking at this issue for few days. Here is how I am setting the category for audio session;

NSError *error = nil;[[AVAudioSession sharedInstance] setCategory:AVAudioSessionCategoryPlayAndRecord                                 withOptions: AVAudioSessionCategoryOptionMixWithOthers | AVAudioSessionCategoryOptionDefaultToSpeaker                                       error: &error];if (error != nil) {    NSLog(@"Problem setting AVAudioSession to mix with others");}

Any help is very much appreciated.