Hi cosnet,
This is only a guess, but the newer versions of InDesign CC pdf files put extra information in the files... They also write out pdf file v. 1.7 which I have had problems with in Scribus...
From Adobe.com "Since ISO 32000 is equivalent to Adobe's PDF 1.7, Adobe is not producing a PDF 1.8 Reference. However, Adobe is publishing a document specifying what extended features for PDF, beyond ISO 32000-1 (PDF 1.7), are supported in its newly released products."
Could you share one of the pdf files for review? Do you still have access to InDesign, if so could you try saving the pdf as version 1.5 and then try importing into Scribus? You mention same problem with Windows 10, which OS were you using before? One last suggestion, have you tried using the 1.5 version of Scribus?
Cheers!
mnawij