opening mac zip files on windows computers

i used to have no problem opening any zip file no matter what. i’ve opened literally thousands of zip files made on macs. around 5 days ago, i suddenly can’t do it anymore, nor can a couple other pc users i know.

i haven’t done an update of any sort in that time, so i’m wondering if macs updated with some new feature that is causing this. it really sucks since i can’t open 1/3 of the blog content sent this way.