updating a multipage placed pdf file changes all the links to page 1

I have a 64 page pdf created in Indesign. 

Each page is just a 2 x 2 inches, so I have placed that file into another Indesign file, 12 pages per page so that I have fewer pages to print and it will be faster to cut out.

When I go to update the link to the 64 page pdf all 64 placed pages change to page one of that pdf. This happens both when I say "update link" when I open the document, and when I don't update when opening and use the Update All Instances button in the links panel instead.

I feel like this has worked just fine in the past which is why I chose this workflow, but it is definitely not working now.

Am I forgetting to press or check something?