@Alexandre1969 

This is somewhat common situation, when someone tries WiFi mesh and finds device in the household that can't work with WiFi mesh. That same device works just fine with non-mesh WiFi.

The first recommendation in that case, when it is Windows device, is to check for new drivers. If there is nothing in Windows Updates, even under optional updates, check on Dell support site. It is possible they have newer set of drivers for your wireless adapter they haven't shared with Windows Updates.

Also, if your notebook has Ethernet port and you can wire it to Satellite M4 with Ethernet cable, that should solve the problem.

Other than that, the process of troubleshooting is to eliminate what could be different in WiFi mesh vs. non-mesh WiFi router. There are very few differences: it is seamless roaming and dual band with band steering (2.4GHz and 5GHz under same SSID).

To turn off seamless roaming toggle "Mesh" off for that notebook in Deco app.  In Deco app open information page of Satellite Deco to which notebook is connected and you'll see notebook listed there with mesh toggle on the right.

To turn off band steering, in Main Network disable 2.4GHz:

If nothing of those fixes the issue, you can also turn off Fast Roaming under Advanced in Deco app. Check its description first, to understand the implications.

Thanks for answering.

I understood the explanations. I already did the test with the ethernet cable and it worked yes. But as I only have two units, one Deco was very far from the other, with walls and bathrooms between them. In that case I believe that a third Deco would work yes.

In fact, the idea was always to connect the work laptop via cable. While I don't buy the third Deco, I took another tp-link router and put it as "bridge", and from this I connect the cable to the laptop. It was stable, but using the 2.4 network. My wife's notebook only works with 2.4, so I can't turn off 2.4 on Deco.

After installing the third Deco, I'll post here how it turned out and show you a map of how the environment was in my house.

Thanks

Alexandre Cortez

Guys, just to conclude. I returned the Deco M4 and exchanged it for M5. But even with three M5 it didn't work well. I had to add one more, then it worked. Still, the internet on wifi doesn't even reach the 500 Mbps I have.

Alexandre1969 wrote

Guys, just to conclude. I returned the Deco M4 and exchanged it for M5. But even with three M5 it didn't work well. I had to add one more, then it worked. Still, the internet on wifi doesn't even reach the 500 Mbps I have.

  @Alexandre1969 

The absolute best I ever got with Deco M5 was 475Mbps. For Internet speeds of 500Mbps and higher you should be looking for WiFi mesh that supports WiFi6. With Deco, it is X-series of their hardware.

For faster than gigabit speeds you will have to research WiFi6E and WiFi7 capable WiFi mesh solutions. Note that your clients need to support these protocols as well. Older client hardware, sold before 2020, is unlikely to support WiFi6, WiFi6E and WiFi7. 

  @Alexandre. 

Yes, what I really needed was speed on my work laptop. I connected a Deco with cable in it and I have an average of 150Mpbs. It's already much better than the 12Mbps I had before. But the conclusion I came to is that Deco doesn't deliver all that is promised in the countless videos I've watched. It all seems so easy and miraculous, but it's not. Plus they are still very expensive. Two Archer C7 in "bridge" maybe gave me the same as these 5 Decos deliver.

The map of my house:

Thanks