A closed funnel means users have to see step 1 of the funnel to be included in the funnel. If a user enters at another step they are not included in your report. The Purchase Journey report (in the standard reports) is a closed funnel, likely, the purchase totals you see here do not add up to the total orders for the period.
You can create an open funnel, in this type of funnel users can enter the funnel at any step and you should see an increase in users through the funnel (including orders) by creating an open version of the purchase journey in Explore.