Sadly ads by certain applications which use "Airpush notifications" can't be blocked. I use two of them, Textra and Aptoide, but have only enabled internet access for one of them (Aptoide) which plays an ad with sound in fullscreen even if the app isn't displayed.
Yeah, I wrote this in the post. You may try "Lucky Patcher", I'm very sure it will work (block Ads) of those stubborn apps.