Xbox One controllers randomly disconnect
I had an issue on my own Xbox One where one or other controller would randomly disconnect and then reconnect few seconds later after pressing A button on the affected controller. After ruling out obvious issues (low batteries, wireless interference, re-pairing, updating firmware), I started looking into hardware.
Original Xbox One Controllers communicate using proprietary Wi-Fi Direct type of connection (newer models added Bluetooth for PC connection, but controller to console connection is still using Wi-Fi). Specific part that manages Xbox One wireless communications is shown below and can be easily find to buy online my searching Xbox One Wireless Board 1525.