I received a PDF file, to be placed in a magazine, with text on a transparent part of the PDF.
When I place the PDF file in an Indesign document the text on the transparent part is not visible.
In an older version of Indesign, CC 2019 there is no problem.

After a chat session of a day with Adobe we find the problem, it’s the version of PDF.
A PDF file made in version 1.3 of Acrobat distiller. When I converse it to version 1.6 the problem is solved.

I think Indesign should support also older versions of PDF files?

I did not expect this problem and it cost me a lot of money