PDF (Advert) looks different as soon as I open it in Acrobat or place it in InDesign...

Hi everyone

I've been using Adobe Acrobat for print magazines for years and now something completely illogical happened: A client sent me a PDF which has been printed correctly last year. I didn't do anything more than opening it in Acrobat and placing it in InDesign and now – after printing the magazine, unfortunately – I see that its appearance had been changed without any note or preflight error. 
When I open it with Macintosh Preview, it looks correct. 😕😕 Has anybody experienced anything similar?
I didn't change anything on the PDF, I just opened it and placed it. 
Screenshot attached: