AdMob Rewarded video ad capping

Question

I implemented AdMob rewarded video ads into my app. Both test ads (test ad unit ID) and production ads (my own ad unit ID) are being shown well. I set the frequency capping to show no more than 3 impressions per user per an hour, but it has no effect and I can watch more than 3 ads in a row. Is it an expected behaviour for an app that haven't been released? I'd like to make sure the capping will work out when the app is on Play store.