Clients install end point definition updates properly but don't send status to the SCCM server

Hi Guys, 

Please help me out in this, i am facing the below issue. 

The issue is the clients computers installs end point definition updates properly but don't send status to the SCCM server, like last update time and date,last definition update version etc.what is the reason behind this and how to resolve this issue?? As some of the system have this issue around 800 out of 7000 Systems. 

I tried one solution that i found from the blog after too much R&D. after this i found a solution that there is folder in the below path named RtBackup. 

c:\Windows\system32\logfiles\WMI\RtBackup 

Take the properties of RtBackup folder and then go to the security tab, here the system is added with full rights, add domain admin group and give the a full rights and remove the system and apply then restart the system, the system update status would be sent to the SCCM server. 

After implementing this some of the systems are working fine but most of the system are not. So please guide me how to resolve this painful issue. Any help would be greatly appreciated!