My second in command over here suggested this afternoon that we run sfc /scannow to see if something got touched by a Windows Update and got corrupted. We didn't end up doing that because it started to work but you might want to give that a try. If you have socket time-out errors on the client machines every 40 seconds until you get to 10 minutes then you have the same issue as I did. It seems to self resolve given a lot of time which leads me in the direction of something on a timer.
Best of luck!
