Product Image not always showing on invoices

Some of the invoices attached to order emails show the product image and some don’t have that column at all. See this screenshot for an order invoice that didn’t have an image column: https://snipboard.io/K1G9oR.jpg. But if I go to “Invoice/Packing, Invoice” from the wp-admin menu, then the Customize tab, I can put in that order number in the upper right “Preview sample” field, and the sample shows the product image! See https://snipboard.io/HBzObk.jpg

On the Customize tab, under “Product table”, “Image label” is checked.
I checked the file sizes and they are small (66KB, 677 x 900px).