If your device is Android and it has an active "Parental Control" (also called "Child Device”), you won't be able to restore your purchase on that device, as Google Play Store does not allow kids' profiles to interact with any “purchase” or “restore purchase” process.
If this is your case, you have two alternatives:
1) Deactivate “Child Device” on your Android Device, and then, proceed to “restore purchases” using the same account you’ve used to create your Papumba Subscription.
Learn how to deactivate that feature on their support website:
https://support.google.com/families/answer/7158477?hl=en
2) You can cancel your current Papumba subscription on the Play Store and then start a new “web subscription” on papumba.com. By counting with a web subscription, you will be able to log in to your account on up to 4 devices, whether they are Apple or Android devices, or have an active “Child Device”.