not importing full first page of collection manifest

[saracarl]

When TN imported the following collection: https://cdm15138.contentdm.oclc.org/iiif/p15138coll54/manifest.json

They only got around 450 items. We would have expected the first page of items -- 1000 of them.

We need to reproduce and see why they didn't get the full first page.