Few objects are not available while running reports

Cause

This default limit of 500 objects is by design 

Resolution

-Create a registry key to manually set the maximum object limit in the Add Object Wizard. 

On the computer that's hosting the Operations Manager console, close all running instances 
of the console.
Start Registry Editor. Make sure that you're using the same user account that's used to 
run the console. 
Locate and then click the following registry subkey: 

HKEY_CURRENT_USER\Software\Microsoft\Microsoft Operations Manager\3.0\Console
Create a new DWORD value key, and save it as MaximumSearchItemLimit. Assign a value to this key that reflects the maximum number of objects that you want to display. For example, use a value of 1000 if you want to limit the maximum number of objects to 1000 instead of to the default limit of 500.

Location: HKEY_CURRENT_USER\Software\Microsoft\Microsoft Operations Manager\3.0\Console
Name: MaximumSearchItemLimit
Type: REG_DWORD
Value: 0 to 65535

Exit Registry Editor.
Reopened console