It can be possible that there is no active subscription associated with your account. So we would ask you to check these steps:
Is the device you purchased your Premium service with connected to your account? If you can see "Sign off account" under the ‘Account’ option then you are connected.
If not, please connect the device to your account to save and transfer your purchased subscription. You can now enable Premium in additional apps (MeteoEarth or AlertsPro) and on multiple devices by: selecting a premium feature, tapping on the “Restore Premium” button and adding your account credentials.
If yes, please disconnect the device from your account (via the option “Sign off account”) then restart your device and register again (via the option “Sign in account”).
If none of the previous steps work please send the invoice of your in-app purchase to our support team. Alternatively you can also provide us with a screenshot of the purchase history, which indicates the premium purchase.