Please click on Database up at the top of the website, find the trunked system in the State/County that you are trying to program in and provide us a link so that we know what system you are trying to work with.
Typically if you have a trunked system programmed in but cannot pick up any activity by scanning it but CAN pick up activity if you manually step through the frequencies in the system, then either the system is not programmed correctly (improperly ordered LCNs, no control channel programmed in, etc.) OR you have one or more of the active talk groups locked out OR you are running in a mode such as ID SCAN and do not have talk groups programmed in the scanner at all. 'ID SCAN' is a term used in Uniden scanners - I don't know if there is a similar term in RS scanners for ID SCAN/ID Search.
But the first step is for us to know what system you are trying to program in - and for that we need a link to that system - Get the SysID or SID from the radioreference database or copy/paste the whole URL of the informational page for that system so that we know what you are working on.
Then we can offer more suggestions as to why it may not be working as you believe it should.
Mike