I was wondering the same thing as @chriscollins Check to see if you can run a manual recon in Terminal first off. If it fails there too then its not going to work in your policy and you'd need to figure out why.
Also, is this happening on all Macs, or just some? What OS versions and what version of the JSS are you using? These could be important factors.
Also keep in mind that the policy may be attempting a recon, but if, due to an issue with the Mac, or a defect in the product, its not able to actually complete the recon, no inventory update will occur. Recon takes place locally through the jamf binary and only when its gathered all the data does it do an upload back to the JSS to update the Mac record. So if it never gets to that final stage for some reason, inventory data doesn't get updated on your JSS.
