This linked image (a PDF made in presumably Adobe Illustrator), with page box set to ArtBox, Minimum Content or Maximum Content and passthrough enabled, gets mangled when exporting the document using the PDF/X-4 preset.
With PDF/X-1 or any digital PDF preset, or the page box set to anything else, the problem doesn't occur.
I attached a package with the document, including the linked image and the exported PDF.
bug.zip