You have upgraded to 8.5 RU3 and have one or more Task Servers that have stopped working as expected. When reviewing the Site Server Settings page in the console for those Task Servers, it shows as needing an upgrade and the version is not 8.5.5030. When you check the installed version of the Altiris Client Task Server Agent, it shows the expected version, 8.5.5030.
8.5 RU3
select vc.name, ts.Version as TaskVersion, ts.Build as TaskBuild, ts._ResourceGuidfrom Inv_Client_Task_Servers tsjoin vcomputer vc on vc.Guid = ts._ResourceGuid
select vc.name, ts.Version as TaskVersion, ts.Build as TaskBuild, ts._ResourceGuidfrom Inv_Client_Task_Servers tsjoin vcomputer vc on vc.Guid = ts._ResourceGuidwhere ts._ResourceGuid = 'PASTE GUID HERE'
update Inv_Client_Task_Serversset Version = '8.5', build = '5030'where _ResourceGuid = 'GUID OF Bad TS'