Class com.yandex.metrica.impl.ob.Ni failed lock verification

[layth5100]

Hello i am trying to use Admob mediation to show Yandex ads (Banner & Interstitial ), Yandex ads not showing i get this warning!

Yandex Mobile Ads 5.7.0 integrated successfully
Yandex Mobile Ads Adapter 5.7.0.0 for Admob Mediation integrated successfully
Yandex Mobile Ads Adapter 5.7.0.0 for Admob Mediation initialized successfully
Class com.yandex.metrica.impl.ob.Ni failed lock verification and will run slower.
Common causes for lock verification issues are non-optimized dex code
and incorrect proguard optimizations.

   Could not instantiate mediation adapter: com.admob.mobileads.YandexBanner (not a valid adapter).
   Could not instantiate mediation adapter: com.admob.mobileads.YandexInterstitial (not a valid adapter).
   Yandex Mobile Ads 5.7.0 initialized successfully

   Class com.yandex.metrica.impl.ob.Ni failed lock verification and will run slower.
   Common causes for lock verification issues are non-optimized dex code
   and incorrect proguard optimizations.

I am using in Gradle

    implementation 'com.yandex.android:mobileads:5.7.0'
    implementation 'com.yandex.ads.adapter:admob-mobileads:5.7.0.0'
    implementation 'com.google.android.gms:play-services-ads:21.3.0'

I followed this guide here:
https://yandex.com/dev/mobile-ads/doc/android/adapters/admob-adapter.html

How to fix this problem? Thanks