I wanted to inquire if there has been a change or if my past success in doing this was because the agent wasn't following policy.

I'm on a flight from SFO to BWI via DTW. Attempted to SDC today to via JFK. In F on the original flight all the way thru. I've done this previous usually with a little prodding on my part since I'm switching to a flight with D1 as opposed to domestic F. This time it wasn't the SFO to JFK flight that was an issue but the JFK to BWI flight. The agent refused to execute the SDC since there was no F available on the flight. I responded saying that flight was operated by a CRJ-200 and that there is never a premium cabin available. Agent stood his ground and refused. So I HUCA and got a different agent. I explained what I was trying to do and she said as long as I was ok with the downgrade and that I would not receive and comp that she didn't see an issue. I said I was absolutely fine with that. After a brief hold she came back and said she could not do the SDC for the same reason the first agent stated.

I've done this before on several occasions both from SFO and LAX. I've always made sure the new flight has space, is valid routing and I'm not going from a connection to a non-stop. As I ended the call with the 2nd agent I pointed out that this makes no sense.. if this is the rule I would NEVER be able to SDC thru JFK to get to BWI if on a premium fare as that flight never has F.

Thanks for the feedback.