2 APNs (Apple Push Notifications) keys already created and try to use one of them to expo build ios. Doesnt' work

We are trying to build an iOS expo app that uses an APN. In the Apple Developers Portal there are 2 APNs already created and have downloaded one of them. Once downloaded we obtain a .p8 file that contains the private push notifications key.

The problem appears when we build the ios app using expo build:ios. After selecting “archive” build, logging to apple developer account, selecting the Team and Provider it asks me to provide the push key, allowing us to select one of 2 options “Let Expo handle the process” or “Upload my own file”:

If I choose “Let Expo handle the process” I get the following output:

Failed to set up Push Key
Failed to prepare all credentials. 
The next time you build, we will automatically use the following configuration:
 (...) 
You can have only two Apple Keys generated on your Apple Developer account.
Please revoke the old ones or reuse existing from your other apps.
Please remember that Apple Keys are not application specific!

The output makes sense because the maximum APN keys that can be generated with an Apple developer account are 2, so expo can’t create a new one.

Then we decided to try the second option: “Upload my own file” and after selecting the path to my .p8 file (that I made certain was right)

And I received the following error: “This Push Key is no longer valid on the Apple Developer Portal”

Has anybody successfully built an iOS app using APNs that already are in use by other apps?