Fix of the issue is now available in InDesign’s latest November’17 update.
Please upgrade to the latest version InDesign CC 13.0.1 for the fix.
If you are unable to see the update, go to Creative Cloud application and click on the context menu on the top right and click on Check for App Updates.
InDesign TeamPaulo C commented
I'm having the same issue but with indesign CC 2017.1 (build 188.8.131.52).
some images are pixelated when exportng to PDF.
If i delete the indesign preferences everything works ok. but some days after this problem happens again.
Upgrading to 2018 is not a option by now because we use Woodwing Enterprise.