Because subscriptions are sold and managed by the app stores Google Play for Android and iTunes fo Apple. Subscriptions don't automatically carry over when a user transitions to a new device. In cases like this:
Step 1: Please cancel your subscription in the Google Play store or the iTunes Store.
Step 2: Please take a screenshot of your RP Diet subscription settings showing your subscription expiration date.
3. Contact us at email@example.com with that information. Our engineering team will make a manual adjustment to your account to ensure that once you switch to your new device, you will be able to use the app until your paid-for expiration date with no additional charge
Note; Your subscription will NOT auto-renew because of this switch. Once your expiration date is reached, the app will prompt you to subscribe once again.