@Ray072 

I have M9 Plus in my Deco mesh and may be able to help you troubleshoot and tune your Deco mesh. From your description the primary suspect for random disconnects would be powerline adapters. Before I can discuss what can be done about it, I need more information from you, specifically:

1. What is the speed of your Internet connection?

2. What are the actual speedtest results for Main Deco, first floor Deco Slaapkamer and (one of) second floor Deco?

3. Run "Test Internet Speed" from the main page of Deco app, what are you getting there? It'll test speed of wired link between Main Deco and Internet.

Also:

4. If you have ISP router, would you be OK to run Deco mesh in Access Point mode? For more info about AP mode, see What’s the difference between Access Point mode and Router mode on the Deco?

5. Please open Update Deco page in Deco app, under More/System, make screenshot and post here (example below) or just tell me what firmware version(s) are reported there. If you had your Deco M9 Plus for a while, they may have come with very old firmware that can't be updated through the app. When that happens, Deco app will report "System is up to date" instead of error message. If this is the case, firmware can be updated manually and I'll explain how, but I need to know your Deco M9 Plus firmware version.

Example:

In that example, all Deco M9 Plus have same firmware version and it is 1.5.6. 

  @Alexandre. 

Thanks for the quick reply!

I wil try to answer your questions as good as possible.

first thing first. I also tought it was the powerline adapters but that doesnt tell me why sometime all of the slave units disconnect. if it was due to the powerline adapters wouldn't only the units "kantoor" and "logeerkamer" be disconnecting? because the rest is directly connected to my switch which is connected to the main deco unit?

1. My contract internet speed is 1Gbit/s (highest i have messured on the deco app was like 800 mbps but ok i understand that there are more factors in play)
2. I have the results from just 30 min ago from my iphone 14 pro on the okra speedtest app standing next to the deco units. the results are:

Downstair:

• Gang (Main deco) 449 Mbps up; 284 Mps down
• Woonkamer 91 Mbps up; 91,3 down
• Schuur 15,1 Mbps up; 6,32 Mbps down

First Floor

• Slaapkamer 90.4 Mbps up; 85 Mbps down

Second Floor

• Kantoor 90,7 Mbps up; 75,3 Mbps down

This are wifispeed. i can test it with a UTP cable if that makes any difference.

3. The speed from the test in the deco app is 635 up and 680 down at the moment. Not fast but its something i can life with.

4. I really would like to keep the deco in router mode because of all the functions. i rather look into remove the factor router from KPN if possible.

5. this is my update page:

  @Ray072 

Your Deco M9 Plus have the latest firmware, which is good. My plan would be to help you tune your Deco mesh performance and also see if it can operate without powerline adapters. I can't tell why different Satellite Deco disconnect, but if after eliminating powerline adapters Deco mesh becomes stable, it means the problem was definitely there.

I see multiple issues with speed test results, so I am going to help you troubleshoot them step by step, from obvious ones. This may take time, as we communicate through this forum and not in real time.

I suggested Deco Access Point mode, because in that mode Deco mesh delivers maximum WiFi performance it is capable of, with anything that is responsible for bandwidth throttling and content filtering eliminated. One could seriously negatively impact Deco WiFi speeds by misconfiguring some of parameters in Deco router mode. It is much easier to troubleshoot Deco mesh in AP mode than trying to figure remotely what might be throttling speeds.

We can try with Deco in Router mode but I may still suggest to switch to AP mode just for the purpose of troubleshooting. After it, you can always revert Deco mesh to Router mode.

Take a look at this document, I will be asking you make Deco mesh configuration changes based on what is described there: How to select a preferred signal source on the Deco App

Let's start with expectations. With gigabit Internet I can squeeze up to 630Mbps from Main Deco M9 Plus, but in almost ideal conditions. Satellite Deco M9 Plus connected by Ethernet to Main Deco should deliver same speeds as Main Deco. Satellite Deco connected wirelessly to Main Deco, with signal Strong or Fair can deliver up to 490Mbps in my speed tests.

Satellite Deco utilizing powerline adapters will be limited by powerline adapter speed, and it usually won't be near what Main Deco or Ethernet wired Satellite Deco can deliver.

So, starting with easiest: your Ethernet wired Woonkamer and Slaapkamer should deliver same WiFi speeds as Main Deco. This is obviously not happening. The fact they both are limited by 90Mbps makes me suspect they negotiated 100Mbps speeds to the switch instead of gigabit, or switch negotiated 100Mbps to Main Deco instead of gigabit.

TP-Link TL-SG108E is managed switch. Login to the switch management interface and check port speeds for these three Deco: Main, Woonkamer and Slaapkamer.

Also, please make screenshot of "Show Map" in Deco app and share it here, example:

  @Alexandre. 
 

thanks for the quick reply again. I have a feeling we are getting further with this.

i took a look in my switch and al the ports where configured "auto" not everything was getting full speed.

so i now forced al ports to 1000MF. Did a restart of the switch and my speedtest at "woonkamer" is 424 up en 230 down. So big improvement there.

still didnt do anything to the powerline adapter or modus of the deco's

  @Ray072 

Excellent. We are making good progress in improving your Deco mesh performance. 

I am assuming both "Woonkamer" and "Slaapkamer" now deliver approximately same speeds: 424 up en 230 down. Which is same as Main Deco. Please double check that for "Slaapkamer" and confirm it.

I am a bit concerned with asymmetrical 424 up / 230 down speeds you see on Main Deco and Ethernet wired Satellites. Do you, perhaps, have VPN enabled on iPhone you use to run speed tests? If you do, please disable it and re-run speed tests for Main Deco, "Woonkamer" and "Slaapkamer". Please let me know if you had VPN on iPhone and if yes, what are the speeds now that it is disabled.

You can keep Deco mesh in Router mode if you are happy with speeds you are getting. If not, switching to AP mode would tell if Deco mesh can deliver more. For now, because we make progress, let's keep Deco in Router mode.

I am going to leave dealing with powerline adapters for later. For now, next step would be to see what is going on with Schuur. You are saying that speed test results for Schuur are: 15,1 Mbps up; 6,32 Mbps down. This is extremely low.

Please re-run speed tests for Schuur again and tell me how Schuur is placed on Main Floor relatively to Gang and Woonkamer. I want to know if maybe Schuur is much closer to Woonkamer than to Gang (Main Deco).

Also, after running speed test with Schuur open its page in Deco app, make screenshot and share it here. I want to see what is in the top part from that screenshot, example:

  @Alexandre. 
 

i double checked the speed and it is correct. And the assymetrical speed where much less. 10 min ago it was 480 up en 460 down. So thats beter.

but 5 min later the woonkamer unit was disconnected for no reason and went back up 3 min later.

I have a vpn but that isnt turned on. So that is not the reason. 
 

to adress the unit "schuur". This speeds are very low stil because this is the only one not directly connected trough backhaul ethernet. But i looked at how it is connected and it is connected to "gang" but "woonkamer" is like 2 meters away and gang is like 10 meters. How can i fix this?

  @Ray072 

This is what you can do with "Schuur". Follow document I mentioned earlier, How to select a preferred signal source on the Deco App , Part 1. Configure "Schuur" to connect to "Woonkamer".

This configuration change, if successful, should be shown in "Show Map" in Deco app. There, you should see "Schuur" connected to "Woonkamer". 

Then, check again speeds for "Schuur". Let me know what speeds you've got now.

After you've done that, please make again screenshot of "Show Map" and post here. I would like to compare it with previous "Show Map" screenshot you made.

@Alexandre. 

Here is the screenshot. Looks like it is connected the way we want. The speed now on de oakra speedtest was 323 up and 309 down. This was right next to the deco "schuur". So this is much better.

So if we can eliminate the powerlines or get them to work properly that would be amazing.

can i just put the deco's in ap mode to check if it will be faster? Or does it need a reset?

  @Ray072 

I think we are done with "Schuur". In proper setup Satellite M9 Plus should deliver about 70% of speed Deco it is connected to, which is to "Woonkamer" in your case. You are getting about that much, which is great.

You made a great choice with Deco M9 Plus. Not every Deco model offers the features M9 Plus can, such as "Connection Preference" and "Test Internet Speed." Either by luck or by proper research, but you've got the best Deco mesh model from WiFi5 capable, and it is pleasure to work with it. 

I think I see the issue with your Decos that use powerline adapters, by comparing two screenshots. I will explain it later, but about Acess Point first. It is possible it may improve WiFi speeds for your Deco mesh, but it will not be by much. To switch to AP mode all you need to do is change setting according to document I mentioned earlier. Deco mesh might reboot and be unstable for a moment, but that's it. 

Note that in AP mode all devices connected to Deco mesh will start getting their IP addresses from v10 ZTE Modem. These will be different IP addresses from what they have now, which means for a short period of time some of devices on your home network might not have access to Internet and may be inaccessible. Most should get new IP addresses quickly, but you may need to reboot (power off/on) devices that can't.

So, I am going to hold with other recommendations until you decide if you want to try AP mode. I would still recommend to try it, because it'll give you the baseline. Whatever you do with your Deco mesh, you won't be getting faster speeds from Main Deco than you will get in AP mode. Same with all other wired Deco. And if they are faster in AP mode, wireless Satellie Deco connected to them will be faster, too.

Which means: if you want to try AP mode - try it, let me know results and if you will keep it or changed back to Router mode. If you decided not to try AP mode - let me know.

When you reply back with that, we will focus on powerline adapters. Everything else, when comes to performance, is properly tuned already. There is still unexplained Decos disconnect, but this we will focus on after powerline adapters. 

  @Alexandre. 
 

let's keep the mode as is because without doing anything i saw my internet was laggy and checked the app. And as i tought everything was offline expect the main and logeerkamer. Logeerkamer is connected to slaapkamer trough powerline. And that one is up. And the rest was down. Because the backhaul was offline for logeerkamer it connected to the main deco trough wifi so very poor signal