@Delboypf 

 

You should be able to get much more from Satellite M5 connected by Ethernet to the network, with mobile device connected to it by 5GHz and with Deco running in AP mode.

 

What I am suspecting might have happened, based on your description:

 

1. The switch through which Satellite M5 is connected is 100Mbps (Fast Ethernet) instead of gigabit, or M5 negotiated 100Mbps speed of Ethernet connection for some reason;

2. The switch is not compatible with Deco backhaul, so that Satellite M5 still uses wireless backhaul even when connected to Ethernet;

3. When you ran speed test, for some reason mobile device you used connected to Satellite M5 by 2.4GHz.

 

To verify all of that, configure you home network the following way:

 

1.  Keep Wi-Fi disabled on sky router.

2. Have Decos in AP mode.

3. Connect Satellite M5 by Ethernet cable to your home network, to make that M5 use Ethernet backhaul.

4. Disable 2.4GHz on Main Network:

 

 

 

After done that, please run the following tests and checks:

 

1. Check that Satellite M5 uses Ethernet backhaul, by verifying what it reports under Signal Source. If Ethernet backhaul is in use, you'll see this:

 

If Satellite M5 not using Ethernet backhaul, you'll see that:

 

 

Instead of "Living Room" you may see different Deco name, depending how you named Main Deco.

 

 

2. If Ethernet backhaul established, check that it is gigabit.

 

To do that, connect laptop or desktop to second Ethernet port of Main Deco. Run speed test from laptop/desktop. Make sure laptop/desktop has gigabit Ethernet card, many laptops and older desktops have Fast Ethernet (100 Mbps) Ethernet port. 

If your device is connected to Ethernet by USB-to-Ethernet adapter, that may not be the good device for running speed test as USB port may be limiting max speed. 

 

If this is Windows computer, install speed test app from Windows app store. For speeds above 100Mbps using app is recommended, instead of running speed test through the browser.

 

When you see speed test from laptop/desktop wired to Satellite M5 reporting speed in excess of 400Mbps, that would mean Ethernet connection from Satellite M5 is gigabit all the way through your home network. 

 

Alternatively, if you don't have device with gigabit Ethernet card to run speed test: install firmware 1.6 beta on that Satellite M5, according to TP-Link support that firmware will alert if Ethernet connection speed is 100Mbps instead of gigabit.

 

3. When you confirmed that Ethernet connection (Satellite M5 backhaul) is gigabit, connect wireless device to Satellite M5, to 5GHz (you have disabled 2.4GHz), verify device is connected to that Satellite Deco and not to Main Deco, and run speed test on that device. It is recommended to run speed test not from browser but from smartphone speed test app you could get installed through app store. For speeds above 100Mbps using app is recommended.

 

 

In my tests with Satellite Deco M5 connected by Ethernet to home network, Deco mesh running in AP mode, mobile device connected by 5GHz, home network and Internet connection is gigabit, I was routinely getting 200-250Mbps in speed tests, and maximum I have seen was 460Mbps with smartphone I use for tests.

 

There is no reason for your wired Satellite Deco M5 to get less than 200-250Mbps in speed tests, unless something is going on in your home network.