Latest Windows update (4/30/15) did something that makes "Go Network" somewhat less reliable. It works, but if both computers share a user name, the Mac seems to like to switch back to files on its own drive, rather than the networked Windows 10 machine.
No doubt, I'll sort this out in a few days, but it can get pretty confusing when it auto switches you to a folder other than the one you know the file is in without telling you.