Interstitial not working in android via cordova build?

I struggle for a few weeks, to up my first game ( Gdevelop 5). on play store. Game logic work fine. but admob interstitial only work if I built from Gdevelop 5 built in system, but when i export to cordova build , the ads not even show at some android device, and always tell me error while loading.
Any body have some problem please?
here is the game link.