The correct action is to uninstall the recently installed game, as it is likely the source of the issue. Since the game was downloaded from a third-party store rather than the official application store, there is a higher risk of it being a bootleg or malicious application. Such applications can cause unwanted ads, degrade performance, and potentially compromise the user's personal data. While performing a factory reset or updating the OS might also resolve issues, they are more time-consuming and might not directly address the root problem caused by the third-party application. It is best practice to address the most likely cause first before proceeding to more drastic measures.