Hey there, jagadesh.
Thanks for posting here in the Community. I can assist you with your question about downloaded invoices in QuickBooks Online.
To make sure I'm on the same page, do these particular invoices read "Unknown Name", or is there a name showing you don't recognize?
As an initial trouble-shooting step, I recommend clearing the cache within your browser. The cache can sometimes become bogged down with older data, potentially causing viewing and performance issues in QBO. This link will direct you to steps for this process, depending upon which browser you're using: https://quickbooks.intuit.com/community/Getting-Started/How-do-I-clear-my-browser-cache-and-temporar....
Let me know how things look after giving this a try, and we can go from there. Enjoy your day.