How are you creating the PDF (i.e. File Save As, or Microsoft Print to PDF) also when viewing the documents is your zoom set to the same level when viewing PDF as when viewing Word document? What program are you viewing the PDF in? It seems i am not able to upload my screenshots as i replicated your documents with Word 2016. The only difference I really see is when I preview the PDF using Microsoft Edge.
Edit...images are posting here they come. All PDF's were viewed using Adobe Acrobat Pro X with zoom at 100% and Word zoom was at 100%
image 1 word doc, image 2 Word saved as PDF, image 3 word doc printed to Adobe PDF Printer, Image 4 image 2 viewed with Edge