Not sure if the flollowing will be of use, but worth a try?…
Try changing the .ai to .eps or .pdf to see if anything happens to see if it makes a difference to importing or exporting as a pdf?
If you have Indesign, try importing the file into Indesign then saving that file as a pdf or/and export as a Indesign eps file.
Sorry I cannot be of any more assistance.
Good luck!