@Vincent-TP Thanks for a prompt reply! So...

1. Are all wireless clients connected to the 2.4G having this issue?  Does this issue persist all the time? or occasionally?

Yep. All devices that I try to connect to 2.4G network don't get an IP. I've tried iOS, Android, WIndows and MacOS. Windows and MacOS get conected to Wifi, but the IP is set to 169.x.x.x (since it seems that DHCP is not accessible). I've tmanually assingned the IP to the wifi card n-on my Windows PC, but that didn't resolve the issue. So now I'm thinking it's completly blocking the traffic on 2.4G

2. If this not always happen, this is mostly because of the channel congestion on 2.4GHz:

The 2.4GHz frequency band is more crowded as it is used by many devices such as cordless phones, Bluetooth devices, and older Wi-Fi standards. This can lead to interference and congestion, affecting the ability of clients to connect and obtain IP addresses. Solution: Use a Wi-Fi analyzer tool to check which channels are less congested in your area and manually change the 2.4GHz channel on your EAP 610 to a less busy one.

How to optimize wireless performance of EAP products

I gave it a spin, but setting different channels didn't solve the issue. As mentioned above - technically I'm able to connect to that 2.4G wifi, but I get no IP (cause potentially all traffic is blocked).

3. In the meantime, please check the firmware version of the EAP, and update it (if any).

I'm running the current one - 1.5.0 Build 20240830 Rel. 63168(4555). Also I've restored the factory defaults and re-configured - but the issue remains.

Some additional food for thought - I've connected the EAP to TP ER2260T router. I wonder if this might be any kind of configuration setting? But if so, why does 5G network work properly in parallel?

Hi  @leciak 

ER2260T  is a router used in mainland China; may I know how did you get that?

If you plug the EAP into your old router, will the issue persist?

What's the encryption mode of 2.4G?

If set it as None, or WPA-personal, and give it an easy password, such as 12345678, not enable any advanced features, will the issue persist?

To be more specific, all clients connecting to 2.4G couldn't get a valid IP address, at the same time, all the same clients can get internet access when connecting to the 5G, is that correct?

  @Vincent-TP 

ER2260T  is a router used in mainland China; may I know how did you get that?

I bought it on the web, it was cheap as dirt (around $180 for a router with 2 SFP 10gbit ports!).

If you plug the EAP into your old router, will the issue persist?

I will try that tomorrow with the Huawei from my ISP, but my concern is that 5G Wifi works properly with the current setup.

What's the encryption mode of 2.4G? If set it as None, or WPA-personal, and give it an easy password, such as 12345678, not enable any advanced features, will the issue persist?

I tried it already, no change. I also made SSID3 with like basic, 12 char password, still no luck.

To be more specific, all clients connecting to 2.4G couldn't get a valid IP address, at the same time, all the same clients can get internet access when connecting to the 5G, is that correct?

This is correct. And this is the case for all devices, regardless of platform. Neither 2.4G nor 5G has VLAN configured.

Can you recommend what kind of logs should I gather from the AP? I saw it's possible to get tcpdump and others, so maybe there is something I can collect from the device?

BR

Michal

Hi  @leciak 

Please do have a try with your old router.

If the issue persists, please let me know. I will create a support ticket, allowing you to send the logs. 

We will analyze the logs to find the reasons.

Hi @Vincent-TP 

Thanks for your continous support!

I've unplugged the AP from my router and plugged it in directly to the ISP router. The behaviour is exactly the same - the SSID 5G works fine (I get the IP from the different DHCP server [and subnet] and the internet/routing works properly) and the SSID 2.4G get's connected (Windows and MacOS as iOS and Android don't connect at all) but doesn't get IP (routing doesn't work?)

Bring in the heavy guns :)

BR

Michal

  @leciak 

Thanks for the reply.

To better assist you, I've created a support ticket via your registered email address, and escalated it to our support engineer to look into the issue. The ticket ID is TKID241125198, please check your email box and ensure the support email is well received. Thanks!
Once the issue is addressed or resolved, welcome to update this topic thread with your solution to help others who may encounter the same issue as you did.
Many thanks for your great cooperation and patience!