Several times now, I've been running two controllers, and one keeps logging while the other stops. Once this happened and the display on the device for that controller froze as well, but it kept working, and a power cycle fixed it. Other times it was just the web that stopped updating.
Then today, both controllers stopped working in the off position. No web updates, no screen updates, no actions. After power cycling, it didn't remember my program, and it may have forgotten my wifi password. (I also accidentally selected a wrong network; not sure if that clears the pw.)
In case this helps, my wifi connection has been shaky. I'm in an apartment building, and there's a lot of 2.4ghz traffic.