Same bug here, I've 05 Deco M9 V1 on 1.7.1, connected to an unmanaged TP-link switch, and the guest network stopped working. As I can see, the guest device can not receive the IP addess :(

  @David-TP 

will this 1.9.1 beta firmware work for Deco m9 plus with HW V1.0 ?

 

Best regards

Jan

  @David-TP 

 

I am having the same problem as Leandro (the previous person you replied to) with my M9's plus v1.0 running fw.1.71
I am not able to get IP's on guest net, I am also using an unmanaged switch.
I believe all problems started with fw.1.6.1

Suggestions?

 

Best regards

Jan

  @David-TP 

So, let's summarize a bit:

• The issue with the guest network was discovered in March/April 2025.
• Since then (I'm writing this post at the end of December 2025, so at least 8 months after the issue was discovered), the only solution to fix the problem is to install beta firmware.
• Some devices (for example, the M9 Plus V1) didn't even get a fixed beta firmware to address the issue.
• While the beta firmware helps, the network is still very unstable.

 

Great job, TP-Link. Fantastic customer service.

  @David-TP Great, that worked.  I had two M9 plusses and the guest networked did not work on the satellite. Now it does.  Thank you.

David-TP wrote

Previously Reported Models:

Deco E4,Deco M5,Deco M9 Plus,Deco X20, Deco X20-DSL,Deco X50-4G,Deco X50-5G,Deco XE75 and Deco BE63
 

Hi, Deco users,
It has come to our attention that randomly, users reported when satellite Deco units are hard-wired via Ethernet cables, no devices can connect to the Guest Network from the satellites and report an error "Couldn't get IP address". However, the same device connects well to the Guest Network of the main Deco, and after disconnecting the Ethernet cable from the satellite unit, the device can also connect to the satellite Guest network.

 

If you have experienced this anomaly, please feel free to leave a comment, including the model number and firmware version of your Deco.

 

Currently, some users have confirmed that restarting the ISP modem again after enabling the Guest Network resolves the reported issue.

In the meantime, the following firmware versions are also provided as a temporary workaround if restarting the modem didn't help:

Deco M4_V1/V2	1.7.0_Official and above
Deco X20-DSL_V1	1.0.4_build_20220114_Beta
Deco X50-4G_V1	1.1.0_build_20230821_Beta
Deco X50-5G_V1	1.3.0_Official and above
Deco E4_V1/V2	1.7.0_Official and above
Deco M5	1.9.0_Build_20250911_Beta
Deco M9 Plus	1.9.1_Build 20250909_Beta
Deco BE11000/BE63_V2	1.1.0_Official and above