Apple Preview con not be trusted with anything.
If the PDF is OK in Acrobat, then the problem is with the other apps.
Maybe tell Apple.
Apart from that: You can open AI files in Preview or Keynote provided that they have been saved with "PDF compatiblity". This embeds a PDF into the AI files, which the other apps then access. Maybe you get better results when you save a copy of your AI files as a PDF. Then try out which options work best.