@JordiB @TP-Link 

After I did a lot of "Network Optimization"s without success, I gave up. I did enable the option to "Disable Ping from WAN" in the IPv4 settings in the Advanced options and then... to my surprise, the Deco's actually connected as desired.

This was before:

And this is right now

But the speed that I'm getting now from "Deco Naty" which is the nearest to my bedroom (and has three wifi signal bars from "Deco Sala" which also has three wifi bars from "Deco Principal") is slower than when both my Deco's were connected to "Deco Principal". My internet service delivers 500Mbps for download and at least 250Mbps for upload (which, near the main Deco is always 500Mbps too) and I'm only getting the speed in the image below, although all my Deco's have three wifi bars 🤔

So, I don't see any improvement or benefit to have this configuration, instead of what I had before 🤷🏻‍♂️

I was expecting at least 300Mbps because they were having strong signal (instead of two wifi signal bars)

@eduardoRoth 

Now you know why Satellite Decos prefer to connect to Main Deco.

Each Satellite Deco is, in fact, advanced WiFi range extender. Google the following for more detailed explanation: "Why do Wi-Fi range extenders cut bandwidth by half"  

@Alexandre. But, shouldn't the Decos use the maximum bandwith available for the 5Ghz band (857Mbps I think) even if my ISP doesn't give me that speed?

That would mean that the first chained Deco gets around 428Mbps and the next chained one would get around 214Mbps? That would make sense to me, if ISP gives me 500Mbps (with perfect conditions) why not use the 357Mbps bandwith left unused?

Well... I guess Ethernet Backhaul will be 😓

@eduardoRoth 

Firstly, 867Mbps is theoretical maximum. In all my tests I never squeezed more than 470Mbps from Main Deco M5, and my wired Internet is gigabit. I am impressed you managed to get 500Mbps.

You are very close to practical M5 limit, so don't upgrade to gigabit Internet to get faster WiFi from Deco M5, you won't.

Secondly, if every of your Satellite Decos has imperfect (not ideal) WiFi connection to next Deco in the chain, expect additional losses there, too.

This is what people smarter than me are saying about WiFi transmissions through WiFi range extenders:

The wireless connections are half-duplex. Although the device can communicate in both directions, it cannot transmit and receive at the same time. The extender communicates back and forth between devices and routers, resulting in loss of efficiency and internet throughput.

For every hop between the source and the destination, the internet throughput through wireless communication channels can reduce by 50%.

...and this is how they suggest to deal with it:

Use an ethernet cable to connect your WiFi extender to the devices and the router as much as possible. It reduces the substantial loss of bandwidth and delivers an improved internet throughput, not exceeding the internet speeds from your ISP. 

This should be good reading for you, especially part that is related to WiFi range extenders (a.k.a. Satellite Decos) placement: https://bcca.org/does-wifi-extender-slow-down-internet/

@Alexandre. do you have QoS enabled? When I updated from 100Mbps to 500Mbps I forgot that my "Total bandwith" was set to 100Mbps, so that was the max I was getting download/upload; after I changed it to 550Mbps I started getting this speed.

I did a network optimalisation with the app and then the Deco goes back to the previous setup. So for as long as you don't do that, it will connect to the nearest one.

In the end I think i'm going to follow the advice and put a gigabit cable to this room so that i can backhaul the deco. Eventually I will need to do that anyway, so might as well do it now.

@TP-Link hello, I'm having the same problem..I have 5 deco M5 in my duplex and the signal strength for everything deco is extremely weak. May I use the beta firmware?

thanks

@TP-Link i have 3pcs of m5...just realized the second floor m5 was not strong enough signal... 

1 on 1st floor 2 on 2second floor...on second floor 1 signal is ok 1 is not ok and both is just nearby

@TP-Link 

When are you rolling out the official firmware update?
The beta one already has several months.