How to increase Admob impression percentage?

Question

Unity

I released an application in the play market with advertising. I made a couple of ad units, connected tokens and at first the ad did not work at all, but this is normal, after a while it starts showing up. But the ad is shown very crookedly. once out of 4 (Approximately). And at the same time he writes to everyone that I have more than 7 thousand. requests and only 600 impressions.
How to increase the share of impressions and what did I do wrong with ad units?

Answer 1

I can see from the match ratio graph that it was small at first, and then fell on the last day. Didn't receive an email about limiting ads? It looks like it.

Answer 2

go to ad block editing and check that you have selected all types of ads and do not set a frequency limit.
In the application control panel (console) on the main screen there is a graph "failure rate" how much do you have?