@TP-Link Except your network optimization tool is garbage. I'll use that and it says perfect. I do a wifi interference test and every deco is on the same channel as everything around it. I think this is more of a problem in AP mode tho. There was an incredibly noticeable drop in performance when I switched then to AP.

Hi same problem here in year 2022 impossible  to select wifi channel on deco x20. 

Deco Lab said that i have a interference in the used channel.... 

  @agustin85 

What I found was that if I rebooted the deco, the channels it used to broadcast were changed.

I figure that it does some kind of check, and chooses the best channels when booting up.

I have 3 access points on my deco system, which all broadcast over the same channels - and I think this is the reason that it triggers a congested network issue in the network diagnostics tool..

Other than the congestion issue; my network appears to be running fine; with wifi running at 270mbps download rate, so it's possibly a badly written tool - which is believable given the basic functionality of the firmware.

I returned a €35 Mercusys HALO H30G wifi mesh that worked mostly fine because it used the most overcrowded channel with no option to change it.

Now I buy a €200 TPLINK Deco X20 because it really looked neat and I discover Mercusys is a low cost brand of TPLINK (facepalm)

The APP and web admin is 95% the same, and guess what, no option to change channel. A 2 year old post talking about promises and intelligent features, but still no manual control.

Does someone know if this network optimization thing does really work or should I start returning this one as well?

  @TP-Link 

It's been two years and they haven't been able to develop this feature?

What are the developers doing?

Why does the system take the most saturated channel? unbelievable.

  a few day ago i upgraded from deco M5  system to x 20 system- from that moment- canot sync my ewelink app with sonnof light switch- the tplink support blames everybody but the them!!

if anybody have a solution - i'll be glad to try (tried a lot  of options)

  @TP-Link 

So when are you enabling this, my deco x20 does not choose the best channel by default.. 

  @JRDe Well, we have another not-happy customer here. I bought the X20 back in December and other than the issue with the channel change issues it's an improvement over what I had, BUT it's a big BUT.  My x20 has decided that channel 6 is the best choice but when I ran the analyzer app I was elated to see my neighbor across the street is also on 6 and the family on the street behind us is also on channel 6. You can probably imagine I was not pleased to find the option to change the channel, which I could always do with my routers over the years, was not offered. It saddens me to see I spent my money to take a step backward. Hopefully, TP will come up with a workaround as I really can't afford another setup.