Advert Loading
Adverts need to load over the network before you can use them. When creating an advert you can choose to "show" the advert immediately after it has loaded. However if it's more suitable for your game you can choose to load your advert ahead of time by creating the advert, but not showing it, then later displaying the advert when you need it. This will prevent your user experiencing a lag while the advert loads. Be sure to check your advert has actually loaded before trying to display it, loading times for rewarded video adverts in particular can be quite long. It's also worth remembering that you are not guaranteed to receive an advert when you request one, so take that into account when you are making your events.
In your events, you have some "show:false" which would likely require to use the Mobile advert appropriate "Show" action.
Also, are you sure that you have set the appropriate Android Application ID for this current game (not for a previous game you have already published) ?
At last, are you testing directly on a mobile device ?
If not, that might be the reason.