How can we have line level notes but not both header and line level notes?

Summary:

Current functionality in RSSP is header level note will apply to the lines once updated but when navigating back to edit requisition summary, the header level notes disappear and only remain on the line level notes. Why are we only able to have line level notes, but not both header and line level notes? We want to understand this functionality so that we can train for it. In Classic version, buyers look to see both header and line level notes, so we want to know if there will be no header level notes that apply on the requisition once