@CGroh 

Thanks for reaching out. I understand that you want to check whether the connection between your main Deco and a second client device is working well, and you’re looking for ways to improve it.

Here are some steps to help you check and improve the connection:

1. For Satellite Deco connection issues:
• Ensure both the main Deco and the satellite unit (second Deco) are placed in open areas, not inside cabinets, shelves, or corners. Good placement is essential for strong signal quality.
• Move the satellite Deco closer to the main Deco. The ideal backhaul signal strength should be at least 2 out of 3 bars, which you can check in the Deco app.
• If you have Ethernet cables attached to the satellite Deco, try temporarily removing them to see if this resolves any instability.
• In the Deco app, go to MORE > ECO Mode (if available), and make sure ECO Mode is turned off for optimal performance.

2. For client device connection issues:
• In the Deco app, check the client list. Select your client device and verify that 'Speed Limit' is disabled, and that 'Mesh' and 'Connection Preference' settings are correctly configured. 'Mesh' should be ON and 'Connection Preference' should be set to AUTO by default.
• Make sure your client device is connected to the nearest Deco unit with a strong signal, and is using the 5GHz or 6GHz band if possible (these bands provide faster and more stable connections than 2.4GHz).
• If you have parental controls set up, confirm that your client device is not restricted by any profile.
• For IoT devices on 2.4GHz, if you have a Wi-Fi 7 Deco, you can go to MORE > Wi-Fi Settings > Advanced and set the 2.4GHz Channel Width to 20MHz to reduce interference. Also, use the 'Network Optimization' tool in the Deco app to optimize your Wi-Fi channels.

Additional tips:
• Make sure all Ethernet cables are in good condition and securely connected.
• If you have multiple Deco units and many IoT devices, try temporarily powering off some units or devices to see if the situation improves.

If you continue to experience issues after following these steps, please contact TP-Link support and provide details about your troubleshooting results.

Let me know if you need further assistance!

@CGroh You can check through the Deco app