Update - There was an issue of communicaiton between the SQL database and the ePO server, just for anyone else who notices the same issue later.
Can you explain more what type of issue that prevent the MSQL from contacting the ePO server? Tha will be helpfull
In my case the actual Windows Server that was running SQL had hung and stop responding.
If ePO is not able to save the Properties and Events (collected from the Agent) to ePO Database you will not be able to see the same in ePO Console. All the Events and Agent Properties collected from each managed Agent are being saved in the ePO Database, and when you try to generate any sort of reports its being fetched from the same Database.
Also, make sure you do not have any Events Purge task running on daily basis (unlikely) to purge all the events.
This might help!