@Amvand
Okay, I understand that after updating your Deco Mesh system to the latest firmware and optimizing your network, your satellite units (connected via both Wi-Fi and Ethernet) are no longer connecting to any devices, even after multiple resets and reconfigurations.
Here are some steps you can try to resolve this issue:
For Wi-Fi 6/6E/7 Deco models (such as Deco X/XE/BE series):
1) If your main Deco and satellite units are from the same package, the satellites should automatically join the network within a few minutes after being powered on.
2) Make sure the satellite units are placed within Wi-Fi range of the main Deco. At this stage, do not connect any cables to the satellite unit's Ethernet ports.
For satellite units from different packages or older models:
1) Before setup, ensure the LED on the satellite Deco is flashing blue, indicating it's ready for setup.
2) If you do not see the 'Add Deco Unit' option in the Deco app's '+' menu, make sure you are logged in with the owner account, not a manager account.
3) If you see the error "Unable to add Deco. Please try again later" after clicking "Add Deco Unit", wait for 30 seconds to 1 minute and try again.
4) If you encounter "We couldn't find any new Deco" or "Failed to add this device" during setup, place the satellite unit closer to the main Deco and try again. If the issue persists, close and reopen the Deco app, then retry.
5) If the satellite unit continues to flash red (disconnected from the main Deco) after setup and relocation, move the satellite unit even closer to the main Deco.
6) For more troubleshooting details, please refer to this FAQ: https://www.tp-link.com/support/faq/1447/
If the issue persists:
• Please contact TP-Link support and provide the results of the troubleshooting steps above.
Regarding firmware downgrade:
• While you mentioned the issue started after a firmware update, TP-Link generally recommends using the latest firmware for security and performance. However, if you suspect the new firmware is causing problems, you may manually downgrade to a previous version if available on the TP-Link website. Please follow official instructions carefully, and note that downgrading can sometimes cause compatibility issues or loss of new features.
Let us know if you need further assistance or have any questions about these steps
