The Premium Pass privilege is linked to the platform account (Apple Account/Google account) used upon the subscription of the Premium Pass, not to the save data of Pokémon Sleep.
Therefore, if you are playing with different save data with the same platform account, the Premium Pass privilege may be transferred to that other save data.
In such cases, any data issues may fall outside our support coverage.
Please wait until the Premium Pass on the other save data expires, and then log in with the save data to which you wish to apply the Premium Pass subscription.
We also recommend registering and using separate platform accounts (Apple Account/Google account) for each device and not playing with multiple save data on the same device.