@ARGamingPK1 thanks for your reply.

 

The QoS is not even enabled. I don't think that's the issue, otherwise it wouldn't work as expected at first and downgrade later.

 

As I saw in other posts, the Deco software will downgrade the speed if it cannot get a "perfect set of conditions". This is all ok but, why does it work for a while and then stops?

 

The same cable that causes the Deco software to force a speed limited to 100MB serves 1GB if I connect it on the ISP modem/router.

All the evidences point to some limitation imposed by the Deco software.

I wonder why I can't turn that off?

Hi  @ARGamingPK1, and thanks again for your reply.

 

For reference, this is the third software version that I'm using since I bought the Decos and I experienced the same issue with all of them.

That said, I think we're missing the main point here. 
The main point is that the Deco is limiting my connection speed after giving me the full speed. So the cable is not faulty.

Also, if I use the same cable from another device, like the ISP modem/router, the connection speed is perfect.

I also tested the cable and it's properly wired and connected.

 

The main point lies around the fact that the Deco limits my connection without a proper explanation. It starts fast and then drops after a while. Where the "while" might be a few minutes or days.

If other devices can work properly with the cable then the Deco should do it too.

 

I considered replacing the cable but that would require me to do radical changes like break a whole wall, that's defo out of question, especially because I tested the cable and it's a good cable, Cat6 STP.

Hi  @ARGamingPK1 

 

Yes I did. When I do it the connection speed works perfectly well.

Hi  @David-TP 

 

Thanks for your reply.

 

I have a TP-LINK 8P Gibabit TL-SG108S switch. This is not a managed switch but it has a loop protection.

I'd like to mention that I bought it specifically because I was having the issue reported in this thread and this was an attempt to fix the problem.

It worked well for a while but then the issue started again. I cannot tell how long it took since I didn't test on a daily basis. Perhaps a couple of days.

 

I have three X50 and 2 x10. All running with the latest stable firmware.

 

One thing that is kind of alarming to me is the fact that you're asking me about the switch.

I have no trouble with it since I work with tech for several years. But I see this product as an end-customer one with the goal to be easy to setup and maintain.

Once you require a managed switch with loop prevention it kind of stops being an "easy to use" product.

 

---

 

The above said, I decided to move to the Access Point mode until I have a definite anwser about the issue I'm having with the traditional router mode.

Please understand that's very time consuming and frustrating to try, reconfigure, try again.

 

Now what I have is:

 

ISP Modem/Router -> Unifi Express Router -> Unifi USW-Flex-Mini Switch

 

From the Unifi USW-Flex-Mini Switch I have:

- One port connected to a Deco X50 (main)

- One port connected to a Deco X50 (child)

- One port connected to another switch (the TP-LINK 8P Gibabit TL-SG108S I mentioned above)

 

The TP-LINK 8P Gibabit TL-SG108S is then connected to:

- One Deco X50 (child)

- Two Deco X10 (children)

- My computer

 

I can confirm that using the system this way seems to be working as expected so far, except for a details.

 

When I open the Deco app I can see that the children Deco are all connected via Ethernet but one. I honestly don't know how to force that to happen.

I already tried to remove and re-add the Deco, restarted it with the cable connected but in the app it still shows me as connected via Wi-Fi to the main Deco.

This Deco that refuses to show up as connected via Ethernet is an X10.

I can assure you that the cable connected to the this Deco X10 I'm refering to is properly setup and gives me full speed when I plug my computer directly.

 

So at this point it would be very nice to understand how to properly setup access point mode with my setup and force an ethernet-cable based connection to all Decos.

 

I've also forwarded all log files to the provided email as per request.