I got an update about this. I was able to fix it by turning off the wifi from the router of our ISP. It seems that the decos and the isp wifi are fighting for channels that can accommodate highspeed....

Hi @GeorgeZ, I have the same issue, I have 2 M4r Decos and 1 E4. Hi @TP-Link My connection is from Main router (ISP Router with 500 mbps speed) > Connects to M4 (Main router) via wired connection. >...