@Kevin_Z 
 

Question 1

There are 8 access points in my network, 4 Archer  AX12, 3 Archer A8s, 1 EAP225-Outdoor. I upgraded my 4 Tenda AC10s to 4 Archer AX12s, when I'm still using Tenda previously I don't experience this kind of problem. (Connection dropout and clients unable to obtain IP address through Archer AX12 access points when using the same SSID as the other access points in the network however the A8s and the EAP225 just work fine). This is unlikely due to network infrastructure due to the Tenda AC10s working perfectly before I upgraded to Archer AX12s which caused the problem. The main router is an ER-605.

Question 2

Auto, enabled and disabled I've tested it all. The problem still exists when using the same SSID.

Question 3

This worked, no more connection dropout or clients unable to obtain IP address however each AX12 should have each own unique ssid. But my use case is that I want to make all of my APs in the network to have the same SSID in order to implement wifi roaming so that the devices automatically connect to the nearest router. It is a hassle to manually connect to the strongest AP whenever I move to another place.

Additionally, I don't know if this information will help. Previously when I setup my AX12s with the same SSID (I experience dropouts and being unable obtain IP address). I've tried setting up a Static IP address in my device. When I did this, my device was able to connect to the access point however it cannot reach the local network or the internet (It cannot reach the main router or other devices in the network even though my pc connected through lan cable of the access point can reach the network). The device can only reach the AP's config website. I think there is a problem in the bridging of the wifi network and the local area network. I think your engineers should look into this. 

Additionally, who is the assigned support engineer in our problem? Kathy said that she has a business trip till tomorrow (September 21). She said to contact Adam but he doesn't reply on the support mail.

  @Kevin_Z 

Beyond this mess around product naming and type, there is I think a slight mess aroung firmware versions and dates. So here's the riddle: which one is the lates (newest, best, ought to be used) firmware (see the attahced picture from TP-LINK Support Website):

  @terziyski 

OK. Assuming that is the latest version, why is the router offering me automatic update?:

Anyway. The original problem is still there. Clients can not obtain IP address with DHCP if they are coming through the AX12. If they are coming from other AP the connection succeeds. Here's the log from the DHCP server.

Sep 20 13:54:29 server dhcpd[29371]: DHCPDISCOVER from [ethernet:address] via eth0
Sep 20 13:54:29 server dhcpd[29371]: DHCPOFFER on [IP.address] to [ethernet:address] via eth0
Sep 20 13:54:30 server dhcpd[29371]: DHCPDISCOVER from [ethernet:address] via eth0
Sep 20 13:54:30 server dhcpd[29371]: DHCPOFFER on [IP.address] to [ethernet:address] via eth0
Sep 20 13:54:32 server dhcpd[29371]: DHCPDISCOVER from [ethernet:address] via eth0
Sep 20 13:54:32 server dhcpd[29371]: DHCPOFFER on [IP.address] to [ethernet:address] via eth0
Sep 20 13:54:36 server dhcpd[29371]: DHCPDISCOVER from [ethernet:address] via eth0
Sep 20 13:54:36 server dhcpd[29371]: DHCPOFFER on [IP.address] to [ethernet:address] via eth0
Sep 20 13:54:43 server dhcpd[29371]: DHCPDISCOVER from [ethernet:address] via eth0
Sep 20 13:54:43 server dhcpd[29371]: DHCPOFFER on [IP.address] to [ethernet:address] via eth0
Sep 20 13:54:51 server dhcpd[29371]: DHCPREQUEST for [IP.address] from [ethernet:address] via eth0
Sep 20 13:54:51 server dhcpd[29371]: DHCPACK on [IP.address] to [ethernet:address] via eth0

The first 10 lines shows what happens when the client is forced to connect through AX12 and is unable to get IP address, and the last two lines, when the client is automatically reverting back to connect to a different, well known AP (with different SSID) and succesfully obtains IP address.

  @Tschabha 

A good solution, if anybody is capable of doing, RETURN it (I already did) and buy another one that works, for example AX53 if you want WiFi 6 or C80 if WiFi 6 is not needed.

Until the issue is solved, then you could buy it again. That is what I plan to do since specwise the AX12 seems good.

  @Kevin_Z 

Olá!!

No meu caso uso dois AX12 / 1500. Saindo da Lan do primeiro e entrando na Wan do segundo (este em modo AP) exibindo 2 SSID o que não quero. Preciso dois conectados via cabo e gerando uma só rede. Tinha os antigos AC20, velhos, 10 anos atras que faziam isso muito bem, mas velocidade limitada. Atualmente, com os modernos AX12 / 1500 easy mesh não é possível nem usando o cabo e nem via wireless. Já verifiquei as indicaçoes sobre DHCP, estão conforme sugestão. Nada acontece.  Entrei em contato suporte via e-mail sem sucesso.