This problem has not only been going on for WEEKS, it has been going on for MONTHS!!!
I first encountered this issue when publishing book covers using PowerPoint and was horrified when my very crisp and clean type font turned into a muddy mess after conversion to PDF.
I finally had to go back to a TimeMachine retained version of PPT v14.
This resolved my issues with the conversion.
I have two copies of PPT on my desktop - the most current version - which I never use because I can't trust it to work properly, and my V 14, which I use daily for my book cover creations.
WHY CAN"T MS SIMPLY GO BACK to an older version of PPT and copy the 'working code' from the older versions that work into the updated versions that don't work?