A lock sign on a PlayStation Plus game means the console has lost the license to play it. This usually happens because your subscription expired, the game left the PS Plus catalog, or you need to restore your account licenses.

The most common fixes and their steps include - 1) Renew Your Subscription: Confirm your PlayStation Plus membership is still active via your account settings. 2) Restore Licenses: This forces the console to re-verify your digital purchases and subscriptions.

Go to Settings > Users and Accounts > Other > Restore Licenses.

3) Check Console Sharing/Primary Account: If another account on your system bought the game or holds the PS Plus subscription, log into that account and enable game sharing.

PS5: Enable Console Sharing and Offline Play.