Since I’m visiting Kodular community, I’ve seen many threads regarding ads problem (talking about admob, I’ve never used any other!). Since I’m using Kodular creator (possibly 2 years), I only have two apps on store, and till now I faced not a single problem regarding ads! In fact, as per my Admob account report, I can see that ads are showing on my new app with only 1 install! Yes, only 1 imstall so far and that is on my own device! 
So, at end, I have doubt on app quality which is facing insufficient ad inventory problem. Spend some time to make your app worthy! I guess, this way you’ll never have that problem again. 
I just shared my experience, if wrong, corrections are appreciated.
