NativeAd callback onAdImpression not run react-native

I am using Admob (react-native-admob-native-ads) package with my react-native(android) app. I have a problem with NativeAd, onAdImpression callback on NatveAd is not called even after the ad is loaded and display on screen. But when i open my app from app-tray onAdImpression called correctly.

Here is my code for NativeAd

<NativeAd ref={nativeAdViewRef} adUnitID={NATIVE_AD_ID} onAdLoaded={()=>console.log('Ad Loaded successfully')} onAdImpression={()=>console.log 'impression count'}/>

Here Ad Loaded successfully printed in concole but impression count not until i open my app from app-tray