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Is your new loan reporting? That is something a dispute with the CRA can't fix, but reaching out to the servicer should help. I haven't heard of any federal servicers that don't report to all three CRAs, and from November to February is more than enough time for it to have shown up.
What is showing on your report for the old tradelines? Did they make any changes? Some servicers will leave the late payment marks, but they are required to remove the default status and any remarks like "claim filed with gov't." Your collection agency that you did the rehab with should have given you a letter when you completed the rehab, usually sending that letter gives the previous servicer(s) all the information that they need to update their reporting. Have you tried that?