Hello @Rohit Nagar
Welcome to Atlassian Community!
Indeed, We have a reported bug in Jira Server where the implementation of HSTS can cause your Activity Stream to display only a blank space instead of its content:
If that's the bug you are facing, please vote and watch that bug to increase its priority and also receive notifications about any updates.
If you have not implemented HSTS in your Jira Server, please provide us the following information:
1 - What is the version of your Jira Server application (7.9, 8.0, etc)?
2 - Check if any errors are returned in your Atlassian.logs at the time you load your dashboard and provide us with that information, properly hiding any sensitive information before pasting it in this community questions:
4 - Try to use a different browser to load the page and incognito mode, checking if the problem still reproduces.
Let us know if you have any questions.