Duplicate applications are not allowed when adding android debug certificate fingerprint to Google Maps API credentials in Developers Console

Question

I have an application for 6 years already on Google Play Store. This app uses Google maps, so I have an API key generated and for this key I have several combinations of app package/certificate fingerprint configured. I need to add new combination for already existing app package, but with new debug certificate. But Google Developer Console now shows Duplicate applications are not allowed:

How am I supposed to have same application there with multiple debug certificate fingerprints? It was possible before and it makes perfect sense (1 release certificate + debug certificate for each developer working on the project). Am I missing something behind? Maybe I just misinterpret the error message. Either way I wasn't able to google any result for this error message.

Answer 1

I found the answer myself short after I posted the question. Basically I accidentally submitted same combination of app package and certificate fingerprint twice sometime in history.