Download Button Missing After Ordered Digital Photos Replaced

I have a collection set up for clients to select 5 images which are included in their session fee. I have it marked to not allow download until I replace the images. The whole process worked fine -- I went into the order => manage photos => replaced photos. But then after that, when I click "View customer order on website", I can see the replaced photos, but there is no "Download" button and no "Download Pictures in a ZIP File" button at the top. So there is no way for my client to download her images. I have confirmed that the item used in the collection is set up as a download. I have been processing many orders the past few months (using a different price list) with replacing photos for orders of digitals with no issues. The only thing different this time is the cost is $0. Please advise what could be causing this issue so my clients can download the digital images they paid for. Thank you!

Looks like it doesn't have a payment status of completed since it was created on the admin side. View the order in the admin, click the Edit Payment tab and set the status to completed.

That was it. I knew it had to be something little I was missing. Thank you so much!