I use Word every day all day. Opened a file a few days ago and formatting was whacked. Page format was changed upon opening to A4, which we never use. Page margins are do not show up as set. The page size (A4) itself is not an actual A4 size.
Opening the exact file on a Windows machine with Word, no problem.
This issue suddenly hit one of my co-workers today, also on a Mac. She experienced the issue with her own files, not shared files with me.
We are dead in the water with Word on Mac.