I've been using a pair of Deco X20 in mesh mode with wired backhaul for 2 months. The main Deco is in the attic and the other is in the living room. Around 20 devices with various configs from Wifi n to ac to 6 connect through the system to the ISP's 150 Mbps optical line. I activated all antivirus features. The setup seemed to work well at first. I tested and got aroung 105 Mbps down and upload speed. Gradually I add parental control profiles to take care of our children devices including laptops (for work) and smartphones (for play).

But after sometimes, the system was gradually getting slugish. My children are complaining that their laptop are lagging. Their smartphones ran out of daily time slot even though thaey did not use them... and now my smart tv was lagging, too, could not play Apple Music smoothly. Finally, my laptop also had problem downloading files and playing clip in Chrome. I can still browse the web but feel slow. I have restarted the both Decos but the problem is still there. To day I could not download a file of 6MB. and when switch to my phone hotspot, my laptop works flawlessly. The problem is the speedtest.net result is ok so I guess it is related to some settings.

Has anyone experienced similar issue? Could you help? Thank you very much.