I have two TP-Link Deco routers: one is the main unit and the other works as an extender. My phone connects successfully to either one, but my laptop only connects to the secondary Deco. The laptop can see the main Wi-Fi network, but whenever I try to join it, Windows reports that it failed to connect. I've already reinstalled the Wi-Fi adapter, disabled and re-enabled it, and tried again, but nothing changed. The laptop still cannot connect even after I turn off the secondary Deco. What settings or troubleshooting steps should I check?
3 Answers
Check the network configuration on both Deco units, especially DHCP settings. It would also help to compare the laptop’s IP address, gateway, and DNS information when it connects through the secondary unit versus when it attempts to connect to the main one. That can show whether the two units are configured correctly as a mesh rather than separate routers.
More information is needed to narrow this down. Please provide the exact Deco model numbers, whether both units are the same model, and whether other devices besides your phone can connect to the main unit. Windows’ built-in network troubleshooter may also reveal whether the issue is related to authentication, the adapter, or the saved network profile.
Try restarting the mesh system, starting with the secondary Deco. Unplug it, wait about ten seconds, and plug it back in. If that doesn’t help, restart the main unit as well, then forget the Wi-Fi network on the laptop and reconnect using the current password.

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