Tried this firmware with a factory reset but my problem persists. Namely that our iPhone 6's sometimes don't reconnect after coming home. I realized this when I bought this router a month ago. Pressed the home button and noticed 3G in the upper left and 2 seconds later it connected to wi-fi. This is on both 2.4G and 5G a/c. After that the phones remain on the network indefinitely. I started to monitor it via the web interface and sometimes they reconnect but most of the time they don't. Even after restarting the router the phones fail to reconnect at times. With an iPad Air 2 (supports mu-mimo) the 5Ghz band is unstable when the device sleeps. It drops connection every 1-2 minutes then reconnects so I have to use it on 2.4Ghz unfortunately. Must add that all devices are on iOS9 DP5 but looking at the developer forums and other sites I cannot find anyone with the same problem so I suspect it is router related. All beamforming options are disabled.