I still get an overprint in my PDF, even after disabling overprint in Illustrator.

Hello, 

I disabled overprint by opening the PDF in Illustrator and by checking off Overprint fill and Overprint stroke (Window > Attributes). I saved it again and after I cheked the PDF on overprint in Acrobat Pro, but I still get an overprint. 

I wonder if I'm doing something wrong? Is there maybe another possible way to get rid of overprint?

You can find the PDF in attachment.

Thanks!