A year of stability but now I'm really struggling with Eero

Hi all

I'm pretty much lost for ideas now, maybe someone can help.

My router is a Draytek 2860, and I have 6 Eero Pros (Gen 2) in my house, with the network set to Bridged mode so that my router does the DHCP, which is what I want.

About a month ago I noticed an occasional issue where my laptop wouldn't get an IP address. It would connect to the Eero network but wouldn't get an IP address. I restarted the Eero network, and the laptop etc. and normally the problem would go away for a while.

The last few days, the problem has become huge, affecting many more devices, from Harmony Hubs to iOS to MacBooks. The symptoms seem to be the same - connection to the network but unable to get an IP address.

On my MacBook, when it's in this state, I can go into the network settings and TCP/IP and click on "Renew Lease". This instantly gives me my laptop its correct assigned IP address from the router. However, this only lasts a few seconds, before it seems to lose this IP address. I can click again to get it back, but a few moments later it has gone.

In the same location right now, my other MacBook doesn't have the issue, yet it's right next to it. Yesterday both had the issue, so it's random.

Harmony Hubs switch from red to green to red to green occasionally during the day, indicating the same problem.

My Sonos controllers started disappearing, and I reset all of them, now I can't get any of them to join my Eero network.

I've deleted and recreated my Eero network, doing a factory reset on each one. I've restarted the network countless times. I've restarted my router a few times, both through the admin page, and via a power reset. Powered off/on network switches (I just have unmanaged ones).

Thing is, this was working really well for a year. But now it's completely stopped working.

My house is wired for Ethernet, so the Eeros are connected via a wired connection. So typically in a room I have an ethernet outlet going into an unmanaged switch which then feeds various devices (Apple TVs, desktop PCs for example), and also the Eero for that location. All wired devices are functioning perfectly. None of them lose their IP addresses in this way, they are rock solid. But it seems that all wireless devices that get their IP address via the Eero in bridge mode are now malfunctioning.

I've replaced my gateway Eero with a new one that I hadn't used, it made no difference.

All I can think of is one of the Eero updates might have broken something? Nothing else has changed on my router, I've not touched the firmware for a year.

Help!