Number of impressions on AdMob Panel and actual rewarded ads doesn't match

I have implemented AdMob Server Side Verification How to verify Admob Rewarded Video Ad on a server?

Everytime the user finishes watcing a rewarded ad, Google Server Makes a GET call to my Server. I verify the signature, then store an entry to my database.

To my surprise, I noticed a discrepancy between the number of API calls recorded and the impression count on the AdMob Panel.

This results in lesser earning than what I actually reward my user.

Server Logs:

ad_reward_audit.dart:52:7) 2024-07-31 00:00:00.000Z: 2 ad_reward_audit.dart:52:7) 2024-08-01 00:00:00.000Z: 3 ad_reward_audit.dart:52:7) 2024-08-02 00:00:00.000Z: 1 ad_reward_audit.dart:52:7) 2024-08-03 00:00:00.000Z: 2 ad_reward_audit.dart:52:7) 2024-08-04 00:00:00.000Z: 35 ad_reward_audit.dart:52:7) 2024-08-06 00:00:00.000Z: 6 ad_reward_audit.dart:52:7) 2024-08-07 00:00:00.000Z: 3 ad_reward_audit.dart:52:7) 2024-08-08 00:00:00.000Z: 5 ad_reward_audit.dart:52:7) 2024-08-09 00:00:00.000Z: 36 ad_reward_audit.dart:52:7) 2024-08-10 00:00:00.000Z: 28 

AdMob Panel:

Am I wrong to think that the number of impression should match the number SSV API call ?

If it should be the case, what other steps can I do to investigate this ? I am making loss at the moment do this issue as my rewards to user actually cost me actual money (Computing time cost on expensive GPU)