If you encounter a situation where "the leased account provided by the platform can launch the game normally, but when switching back to your own personal account, it prompts you to purchase (or a padlock icon appears)", please do not worry.
Reason Explanation: This is usually because when you logged into the leased account, the system failed to automatically complete the "primary console authentication" (i.e., console sharing permissions were not enabled). You simply need to manually enable this permission to resolve the issue.
Please view the corresponding solution based on your console type:
I. PlayStation 5 (PS5) Manual Authentication Guide
II. Regarding Nintendo Switch (NS)
For Switch players, under normal circumstances, after successfully adding an account and setting up the "Virtual Game Card" according to the tutorial, there are no such permission issues. Therefore, NS users do not need to perform any additional authentication operations. Once the download is complete, simply select your own personal account directly to launch the game.