@d0ugmac1 

Thanks for replying, I guess I should have included the steps I've already taken to try to resolve this issue, I started with a reboot of the router but this had no effect so then as the other devices had been up for quite a while I decided to just reboot everything however the problem persists 🙁

  @d0ugmac1 

So the ER605 has been forgotten and then adopted but if anything things are worse, before there were 4 or 5 devices that weren't working now I've lost 3 smart speakers too.  1 of the original devices I've been having an issue with is a Google Nest speaker and since forgetting and adopting the ER605 that is now showing an IP address when viewing the client list whereas before it was blank and initially it was working but a few hours later and if I try and use it it just says "hold on while I get connected to the internet" and there is nothing of much significance in the logs, I just see some "[Failed]xxx failed to connected to xxx with SSID "xxx" on channel 48 because WPA Authentication times out/failed.(1 time in a minute)"

For the 3 smart speakers that have now stopped working I don't see any of the WPA time outs and again they each have an IP address when viewed in the client list, although one of them is displaying an APIPA address, but none of them are contactable over the network.

Based on what I've seen on a couple of PCs recently when they've had a similar issue I expect none of these devices have a gateway address assigned, any other suggestions?

I have been able to get a couple of devices reconnected today including the Google Nest speaker and at one point all 3 smart speakers were working but 1 of them has since stopped working and is showing 169.x.x.x address in the client list.  

One other thing of note is that my phone dropped it's connection to the SSID it normally uses and wouldn't reconnect so I tried it on one of the other SSIDs and it connected fine, for the normal SSID I have the phone set to use the device MAC so I can set a fixed IP for it and assign some security rules, when I changed it to use a randomised MAC instead it connected fine to it's usual SSID.

I remember when I first got the Omada kit and there was an issue with DHCP and the sorts of issues I'm seeing now are all very familiar, one of the previously released firmware updates seemed to fix those issues and it has been fine for a long time but now it's looking like the most recent firmware that was supposed to specifically fix DHCP issues has instead re-introduced some old previously fixed issues, which is very disappointing :(

  @Virgo 

It seems to only be wireless clients and no assigning a static IP doesn't work unfortunately, nice to see they're still actively working on firmware but there is no mention in the notes about fixing DHCP issues so not sure if it will help or not, I was actually thinking of going the other direction and downgrading to 2.1.1.

Yesterday through a combination of using the old trick of editing the settings for each vlan and clicking the update DHCP range option then setting the range back to whatever you had and saving along with a reboot of all the APs I actually managed to get everything reconnected and working.  For some reason this morning though 3 of the APs decided to disconnect, they all reconnected fine but it has upset 2 devices and they are now showing connected but with no IP again, could be time for that 2.2.1 firmware to be installed!

  @Virgo 

Most devices have been working the last few days, the most noteable exceptions have been a smart power strip and a Google nest speaker which wouldn't reconnect no matter what I tried and then this morning a PC which was working fine yesterday when switched on today connected to the WiFi fine but was reporting no internet but as it is a PC it did at least offer a chance to do some fault finding.

The PC is set to connect using DHCP and doesn't have a DHCP reservation configured in Omada.

It connected to the WiFi SSID and picked up an IP, gateway and DNS details correctly.

I could see it in the clients list in Omada with the correct IP.

On the PC itself however I was unable to ping the gateway hence why it was reporting 'no internet'.

It was able to ping a couple of devices on the same VLAN but not all, it was able to ping my phone for instance.

I configured the IP manually and used a different IP from the same subnet, set the gateway and DNS and still it was unable to ping the gateway.

I set it back to DHCP and it picked up the exact same IP it had previously and was still unable to ping the gateway.

I tried a ipconfig /release & ipconfig /renew and it picked up the same IP again and was still unable to ping the gateway.

I uninstalled the network adapter in device manager and rebooted, then reconnected to the SSID and it picked up the same IP again and was still unable to ping the gateway.

I turned on the wifi hotspot on my phone, which is connected to the same SSID and instantly the PC had normal connectivity again, it was able to ping the gateway and was working normally.

I reconnected to the WiFi and again it was unable to ping the gateway.

I then configured a DHCP reservation for the PC but it still wasn't working or at least not straight away but then miraculously an hour or so later it suddenly started working and is currently good.

So as you can probably see above the one consistent element is an inability to reach the gateway even though the correct IP address and gateway is configured, I presume that this is the same for the other devices too because I can see them connected with a correct IP in the client list but I can't connect to them via their respective apps.

The fact the the PC worked perfectly fine when connected to the same network via a WiFi hotspot on my phone shows that there is no issue with the PC configuration which leads me to believe there is an issue with the gateway which is of course the ER605, so maybe as Virgo suggested this isn't quite the same as the DHCP issue others have had but it is an issue none the less.

Anybody have any bright ideas what to check, surely there must be some logs to look at that would give me a clue to what's actually going on?