Chrome browser issue with uploading file into WTDocument

We've had a couple users who have reported issues where they can't attach a file (pdf or doc) into a WTDoc, either in the associate new command or the replace content command.  the browse button opens and allows a file to be selected, but normally you then see a green bar load right under the file name.  it works for me, but the other people that bar just stops part-way and nothing uploads.  It works for IE and Firefox, but not for Chrome or Edge.  Must be a setting somewhere, but we've opened up pop-up blockers and cookies and everything seems matched as far as we can see.  not exactly sure what other settings might be influencing the Windchill behavior only on the Chromium engine, but I'm open to ideas.  thanks!