I have encountered a problem in Acrobat DC when trying to redact certain PDFs (not all) whereby a certain area or block of text will be selected, typically near the bottom (footer), I choose to repeat mark across a specific page range, and after applying the redactions, the same area or block of text will be redacted on additional pages throughout the PDF. What's interesting is that if I redact using a black fill, only those pages I selected will be correctly redacted while the other affected pages outside the page range will have no fill color.
I've experienced this issue on different versions and different platforms on both Windows 7 SP1 (Classic v2015.006.30243 and v2015.006.30306) and Mac OS 10.12.5 (v2015.006.30033). This leads me to believe it is a conflict with the redact feature running on certain files.
Any help is greatly appreciated as individual redactions for large PDFs is very time-consuming.