Deco M4 Ethernet Backhaul - QoS issue
I have a strong suspicion that QoS is not working.
My set up is an Ethernet Backhaul, briefly:
Router -> Main Deco (in Router mode) -> TP-Link Switch -> 2 other Decos on 2 different floors connected via ethernet cable.
There's plenty of devices connecting but I've set in the priority my laptop and my mobile phone. I have noticed that when another computer (not on the priority list) runs a game (Fortnite) then it takes pretty much all of the bandwidth and my 2 devices (on priority list) are pretty slow and that doesn't seem to fix.
All of the Decos are M4 models and devices are connected either via WiFi or via cable directly on the 2 secondary Decos.
My main router does have DHCP enabled and I know that it is recommended to switch it OFF but this operation is on a different subnet anyway and I don't have any other devices connecting to the main router apart from the main Deco.
Is there anything else you would recommend I should pay attention to? Or has anyone else seen a similar problem?
Thanks in advance.