I have the same problem. Infuse on my ATV4, iPhone 6S and iPad mini all used to be able to connect to my NAS over SMB and to my Macbook over SMB but now all 3 fail. This makes Infuse on my ATV4 useless since I can’t connect to anything, and very hard to use on my iPad and iPhone since I have to use iTunes to copy a file that I want to play.
I am using Infuse Pro v4.3.4.