Lottie iOS animation is not working in mobile

We’ve tried to implement Lottie animation in iOS app. we added a json file which works fine in android and web but not in iOS i.e., title is invisible and extra lines are appeared on background. here’s code snippet used to play Lottie animation:

    animationView = .init(name: "experts") // json file name
    animationView?.frame = view.bounds
    animationView?.contentMode = .scaleAspectFill
    animationView?.loopMode = .playOnce
    animationView?.animationSpeed = 0.5
    animationView?.play { (finished) in
        // animation is finished

Lottie iOS version - 3.3.0
Xcode version - 12.4
iOS version - 12.5/15.3