@Yiu Since i Purchased my first three Deco M5's +2 late last year i too have experienced the "Static RED light" of no service.

I have on some occasions rebooted the main unit numerous times, and then fingers crossed it works. Reboots don't tend to be a sure thing to fix the issue.

Most recently i set the Main M5 to have a static IP address on my Virgin HUB, and for these last 2 weeks its been solid, until yesterday.

since then, i have rebooted my Virgin HUB. There were no internet issues connecting to the Virgin hub from my iPhone before or after the reboot.

The Main M5 has been rebooted more than few times now.....Still Static RED.

I was quite surprised to see that the TP-Link reply in this thread was querying the OP's Topology. Considering the Deco M5 is as a Domestic solution as opposed to Business solution, i can't imagine this terminology would be helpful to a vast amount of your loyal customers like myself.

Can somebody please give us a definitive answer to resolve the Static RED light issue. something is surely wrong and needs looking into, if the system is stable for 2 weeks then decides quite randomly not to work.