@koudman2 

Same issue here.  I initially had a 3 unit M5 that I was using since 2020. August of 2022 I purchased a 3 unit X55 and put two of the M5 as satellites in two of the rooms where the signal was still somewhat weak and had them connected via ethernet backhaul back to the main X55 via a 8 port unmanaged TP Link switch.  All had been fine until about 2 weeks ago.  Both M5s randomly reboot but the X55 are still online.  To try and eliminate the unmanaged switch, I connected the ethernet directly to my laptop and setup the M5s wirelessly to the X55.  Still having rebooting issues on the M5.  I have seemed to isolate the issue may be when I'm on a WiFI Cell phone call and lots of packets are moving to that M5 and it chokes it OR I'm checking email or downloading a file on my cellphone that is connected to that M5.  My son's M5 also rebooted when he had a gaming system that was on WiFi started downloading a game.  Never had this issue until around 2 weeks ago.  Last firmware for the M5 was Aug 2022 (firmware 1.6.1) and X55 firmware was April 2022 so nothing new from a firmware perspective that would coincide with the issues I started having.  Are you noticing the M5 starting to blink red when this occurs?  That's what is happening to mine.  It "clears" up in about 20 seconds but during that time there are issues, assuming the wireless devices tries to connect to one of the other mess hubs since the M5 closest or that it was connected to goes offline/reboots.

  @MrJSpinny 

Thanks for the answer! Seems like we run a similar setup, I am also using the latest firmware on all my Decos (1.1.8 on the XE75 and 1.6.1 on the M5s). I have my M5s connected through an unmanaged switch to my main Deco as well. Drops seem pretty random so far...

I will turn the leds on to see whether they blink red when it happens as well. Like you described it lasts 10-20s so it might be a reboot and the laptop not connecting to another online Deco in the meantime (10s dropped Teams call).

Hoping some more people respond and we can narrow it down to some kind of solution :-)

  @koudman2 

Hi.

I have a different setup with only 2 M5's connected using ethernet backhaul. I have them set up in the same way for almost 4 years now and without issues.

About 2 weeks ago Teams meetings started stuttering on several computers.At the same time, internet usage became sluggish on every device (PC, tablet) and independant of the connection (Wifi or Ethernet).

Did all the troubleshooting steps and cable swapping and in the end it seems to be something with the M5's, but I don't know what. Nothing changed. Not even a new device on the network.

At the provider's router I get the agreed speed 500/100, Teams works well and internet is a breeze. I also temporarily reactivated the provider's wifi just for troubleshooting and all devices connected to that router work fine. Moving back to the Deco network, the issue reappears.

The odd think here, is that if I run a trace using the M5's altough the performance issue and Teams issues exists, there is never a single failed ping.

This is what I get for more than 6 hours of continous trace (192.168.0.1 is the Deco setup, 192.168.1.1 is the provider's router):

  @Construga Thanks for your input! Same situation here nothing changed in my setup but the problem is real.

Would it be possible that something changed on MS Teams side that is triggering the issue on Deco M5 side? Probably more a question for the Deco Engineering team as that will be very hard for us to narrow down...

  @ImtiazAli 

Thanks for the information.  Unfortunately it's not only Zoom that is causing this issue with my M5s, it's also any large file downloads, me on a Cellphone call that is using WiFi calling.

Other issue is that since my main Deco is now an X55, the UI/Option are not the same as when I was using the M5s.  It does have QOS option but it's basically only giving each device a high priority vs the M5 allowed you to not only give a device high priority but also a certain "Service" that i'm sure relates back to known Ports being used for that service.

In the initial troubleshooting I had with Deco/TP Link tech support they had me remove Beamforming (which I had on) but the problem still happens only on my M5s and that's an issue for me because I put the M5 as both a wired backhaul and then just wifi connected sattelllite so when it crashes it impacts my WFH situation.  Now I've connected my laptop directly to the ethernet I was using for backhaul so my laptop is more stable but now my cell phone or table that uses the M5 via wifi causes the M5 to reset a few times a day when lots of data moving to the M5 from the end device.

  @ImtiazAli 

Thank you for the suggestion.

In my case it's also not just Teams. Every kind of content seems to be sluggish. I tried several solutions and KB articles but none fixed it.

Today I've spend some time checking everything carefully again (cabling, connections, reboot every device including provider's router, etc.)

I wanted to avoid performing a reset and reconfiguring everything from scratch although I felt tempted to do so. <---I'm desperate

But then I remembered my M5 kit had 3 devices and I only installed 2. I could try replacing the main device and see if it improved, but still lots of reconfig to do.

Luckily it's something supported. (  to TP-Link for this). I found this article Changing the Main Unit for your Mesh Network - Home Network Community (tp-link.com) with the instructions to do so and everything worked as expected.
The only difference I found was that the 3rd device had never been used so after adding it to the network I had some additional steps to upgrade it's firmware.

Just finished replacing it and at first sight the sluggishness seems to be fixed. Web pages now load faster. Before when I tried to open a web page it stopped for a while as if searching for something... and then opened. The page loaded and then the images...took 1 second and showed up. Now they open quickly.

I will keep testing it and post the results, but it's as if the main unit was worn out or maybe the software got corrupted or something.

The only things I found so far:

- devices connected to the second unit (the one I did not replace) now work faster, but the overall internet speed is never above 200 megabits. Same test on the newly replaced main deco is instantly 500Mb. They are connected using ethernet so no reason for the speed drop unless the second deco is also failing. I tested the connection without the M5's and it's fast, so I doubt is a cable issue.

- the antivirus/parental security feature that on the old main device reported active for ~1.400 days now says it's brand new and active 0 days.

Maybe the second device also needs replacing. If that's the case I'm willing to buy an isolated unit, but I really need to understand what is happening before spending more money on another one.

  @koudman2 

I had a seperate support case open and TP Link support after having me to very basic troubleshooting came back and said it appears my M5s are defetive and if they are still under warranty they can replace them but if not, so sorry.  I pointed out when I searched this site it appears this is an issue when M5 are being used as satellites off newer Deco mesh systems so could be something in the firmware as well on the main deco.

I just checked and appears there are firmware upgrades for both my X-55 and M-5 so going to upgrade and hope they realized the issue and it's under the "Improved system reliability "improvements" 

I'll report back here after the firmware upgrades to see if it resolved the issue.

  @MrJSpinny Really hope this works but my XE75 and M5s were running latest firmware and continued to have issues. I upgraded the M5 to X50s and haven't had any issues sense... For me it seems to be something in the interaction between the M5s and the newer Deco access points (like you mention) but I didn't want to wait around for a solution as the problem kept occurring on a daily basis.

@koudman2 @MrJSpinny @ImtiazAli 

Hi.

Some additional feedback from my side after a few days of testing.

In my specific case it appears it was a hardware failure.

After replacing the main M5 the issue was fixed for devices that connected to it. Devices connecting to the second M5 that I hadn't replaced still had all the previously described issues with Teams, web surfing, etc.

I ended up purchasing a replacement M5 unit and swapped that second unit (got one for 74,77€). Everything works fine now.

I was curious about the problem and wanted to make sure it was not a software issue, so I tested the old unit. Reset it, added it to the network and reinstalled the firmware.

Anything connecting to it started immediately having problems surfing the web and using teams.

I assume the hardware was worn out or something. It has been in use for ~4 years now. I hoped it lasted longer.

A small hiccup with the replacement: the mobile app did not recognized the new deco as needing an upgrade. The main M5 already had the latest fw (1.6.5). The second one I added to the network had an older 1.6.1, but although the app itself showed it as having a lower version firmware, if I pressed the button to check for upgrade it said no upgrade was available. I had to download the latest version from the website and upload it manually on the web interface.

Maybe it was because the new deco has a different hw version. The main deco is HW 1.0 and the secondary one is HW 3.2.