You should contact an attorney from Jefferson Parish who is experienced with probation violations. The attorney can get copies of the paperwork from Orleans to show that the charge has been dropped and the contact the probation officer and file a motion with the Court if necessary.
When you pick up a new case while on probation two things happen: a new complaint is filed and the procedure to revoke your probation is instituted. The new case can be dropped if the prosecutor decides to proceed on the probation violation. Even though the new case is gone, the PV can be based on the underlying conduct in that case.
Only the court or probation officer can lift such a hold. Contact a criminal defense attorney. If the charges weren't prosecuted then it might be possible to lift the hold.