I recently had a background check run for Amtrack work the guy said it came back Robbery-Parole Discharged, however I was never on parole. I was sentenced to 2 years probation. And the officer said Discharged is not a term he has ever seen used that way.

Here is what Nebraska says. Many States use similar wording. I don't know where you are.
83-1,118 — Board of Parole; parolee; discharge from parole; when; Department of Correctional Services; discharge from custody; notice of civil rights. - Nebraska 83-1,118 — Board of Parole; parolee; discharge from parole; when; Depart

I was never on Parole or sent to prison

I check was run in the DC area

First to add more info, answer your own question, don't use the comment box.

Next does not matter where they run your report, the NCIC report is national data base.

It means you need to go back to the court and get the issue cleared up, since it sounds like you were on parole not probation.

Did you serve some "jail" time