Reward videos not works

The rewarded videos only load in companion, I have 3 screens and in each of them there is a rewarded video. when exporting the apk, only one of the 3 videos works, while in companion all work correctly. Can someone help me please? Thank you very much!

The application is already available in playstore

In which screen only works??? Screen1 or in the others you created???

other screens, screen1 has no ads