Problem with black color when making a pdf from InDesign

I have a problem with black color. In my document in InDesign the copy is in CMYK (0,0,0,100). Full key-color and nothing else. Looks fine.
But when I send the pdf to our printer they say that the copy is in CMYK ( 76,67,62, 85) I have no idea why this happend. I double-checked the color in my document
and made a new pdf (profil: converting all colors in my document to Coated FoGRA 39. Same profile that I allways use and nothing has happend before.
Hoping that someone on this forum might be able to spot the problem for me.

 

 

I didn’t find the right solution from the Internet.

References:

http://www.graphicdesignforum.com/forum/forum/graphic-design/printing-and-prepress/1634952-problem-with-black-color-when-making-a-pdf-from-indesign

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