I recently purchased AC2800 and use it in router only mode (connected to a Virgin Super Hub 3.0 in modem mode). One of the main reasons for purchase was for QoS so I could prioritise my streaming devices and online gaming on PS4. However, as soon as I enable QoS all devices have connection issues. I included my laptop/phone in the middle priority with 45% priority and even browsing the web is intermittent. Any advice much appreciated.