@Atanu SenBased on my Pega experience, unexpected shutdowns of a Pega server can be caused by a variety of factors, including issues with the server infrastructure, application configuration, or database connectivity. In your specific case, the fact that the server starts up fine but then shuts down on its own after a few minutes without any indication of why could indicate that the issue is related to the server infrastructure or application configuration.

One potential cause could be a memory leak in the application or server infrastructure, which could cause the server to crash after running for a certain period of time. Another potential cause could be a misconfiguration in the server settings, such as incorrect values for timeouts or memory limits, which could cause the server to shut down unexpectedly. 

In my personal experience, I have seen a similar issue with a Pega server that was caused by an issue with the database connectivity. In this case, the server would start up and run fine for a while, but then suddenly crash without any clear indication of why. After investigating the issue, we found that the issue was related to a misconfiguration in the database settings, which was causing the server to lose its connection to the database and crash.

To resolve the issue, we reviewed and updated the database settings to ensure that they were configured correctly. We also implemented a monitoring system to track server performance and detect any potential issues before they could cause the server to crash. 

Based on my experience and expertise, I would suggest that you check the server logs for any error messages or indications of the cause of the issue. It may also be helpful to review and update the server and application settings to ensure that they are configured correctly. Additionally, implementing a monitoring system can help to detect any potential issues before they can cause the server to crash.