803s been working flawlessly for 6 months. A couple of weeks ago, we started having problems with logging in to either the 2.4 or 5.0 band. After a lot of debugging and looking at packets going back and forth, found out that the router would not authenticate users after being on for 24 hours. As long as computers stayed connected, everything was fine. If any computer/phone disconnected and tried to reconnect, the device would associate with the 803, but would not authenticate with password. Have updated to latest firmware without fixing the problem.
I first thought it might be a dhcp problem, but after giving all computers a fixed ip and dns servers, it still acted the same. Have tried resetting to factory settings, with out joy. Tired moving it to a different location, no joy. Checked for other wifi access points that may be new in the neighborhood and made sure ours was on an unused channel. Tried different combinations of 802.11ac/a/b/d/n. No joy.
Being a network engineer, I can confirm the problem using Wireshark to inspect the packets to see what is going on. You can see the device associating with the 803, password passed to 803, 803 disconnects.
The only temporary fix is to unplug the 803 (reboot). If I reboot daily, things seems to work until someone turns their computer off and tried to reconnect the next day.
I just need to find out how to return it and get if fixed.