PDF not optimized to Acrobat1.4x
I exported a Pages book file as a PDF to that it could be uploaded to Kindle Create to produce their kpf file so that my book could be published on Amazon. The kpf file uploaded fine, but Kindle Direct Publishing could not process it. After weeks of back and forth their help desk found and fixed the issue, which they identified as "PDF not optimized to Acrobat1.4x." I have not idea how to correct that on my end. Has anyone else ran into this, and if so, what did you do?
MacBook Pro 13″, macOS 13.7