Microsoft 365 features that help users manage their subscriptions, account settings, and billing information.
To better understand the situation, are you paying for the subscription through the Google Play Store or directly through Microsoft?
The best way to determine which Microsoft account has the subscription is to sign in at the following page using each of your available Microsoft accounts:
https://account.microsoft.com/services
Please remember that a Microsoft account is required to use a Microsoft 365 subscription. If you purchased the subscription through Google Play, the Gmail account may manage the payment, but the Microsoft 365 benefits are linked to the Microsoft account that was signed in to the Microsoft 365 app when the subscription was purchased or activated.
Therefore, the Gmail address is not necessarily the account you must use in the Microsoft 365 apps—unless that Gmail address has also been registered as a Microsoft account.
Please let me know where you purchased the subscription and what appears on the Services & subscriptions page so I can continue helping you.