App Uploaded in Play Store but not showing ads in above android verision 7


My app got approved on Play Store on 23 April 2023. Ads are not loading and showing error code 3. So, I just googled it and get to know that Google is ads deficient so Google is not able to provide the ads in my app.

But it was more than 10 days. Only below Android 7, ads are showing and above that, no ads are showing.

Can you tell me why this was happing?

What I had done to solve it

  1. Changed positions of ads,
  2. Load the ad when the new activity started and show it whenever required.
  3. Main screen has only one banner ad, the Workout screen has 1 Interstitial ad (Shown and Load When the Activity started) and 1 rewarded ad (Loads when the activity started and Shown When the user completed the workout).

But ads are showing below Android 7, not above that.

App Link: