InDesign CC 2018, random blurry images in PDF

I am exporting an indd to PDF (print) at High Resolution default settings.

All of my links are up to date. All of the images are adequate size and resolution (300dpi). The images look fine in InDesign with Preview set to High Quality.

InDesign CC 2018 is exporting low resolution, pixelated images. I checked the exact same files from a month ago and they look fine. I uninstalled CC 2018 and reinstalled CC 2017, and the same file exports perfectly from CC 2017!

Come on, Adobe!! What's the deal with this update?