Carto PackageManager return null on Xamarin.iOS

Question

I have such problem:

On Xamarin.IOS Package Manager returns null after invoking GetLocalPackage(packageId) in several places of the application;

What do I know about the issue:

1. This happens immediately after downloading of map package. In other words, in other places of app this work normally;
2. Maybe invoked not on main thread;
3. Reproducible only on 5 and 5C and 5SE iPhones, but on 5C, 5SE in one case less than on 5;

I am supposing that it has some relation to the device performance. Any ideas whould be usefull.