@David-TP 

Dns DoH issue was solved. It seems to be an issue with my former ISP.

Now, I'm using a ftth gigabit connection but I cannot get the full speed over wifi6 devices. I rolled back to 1.6.1 but it's seems limited to 800 MB. I can get the full 940MB using a wire to the deco, so it seems that there's a limitation coming from somewhere. 

 

Thanks.

Hi, How is your topology that are you using? Do you have switch between the Decos? I`m suing ethernet backhaul since my M4 versions and didnt face sny issue! (curernt using X50) If you are using switch, make that you are using the tp-link switchs..

  @Pronomis 

feel sorry for you too. You think that all of us that selected something different for our needs made a terrible decision.

next time it will be better to submit your problem and look for a solution in forums like this one or submit a ticket to the store that you bought a problematic device.

 

Airport Extremes and expresses was state of the art 10-12 years ago . Nowadays are obsolete devices that have security flows , incompatibilities, slow speed etc. 

Better look something that has more security features, increased speed and compatibility. There are too many options from different companies that will work with your needs, do a search I am sure you will find something. 
Have a wonderful day !

  @chls_84 

Topology is:

 

ONT provided by the isp, Deco X50 as the main router (seted up an access point). Then, tplink switch, and 2 Deco X20 and 1 X50, all wired with utp cat6 cables.

 

As I said, if I connect with a wire to any of the deco I get the full 940 MB. If I use any wifi6 device, I cannot get the full speed.

 

Thanks 

Offtopic:

  @Pronomis 

You should buy Asus Zen-Wifi BT10 and get rid rrom this forum.

Apple makes products for dumb persons, and some of them actually believes that are the king of the world for been able to afford them.

 

Ontopic:

Decos are having some issues lately. I was thinking to moving to X80, but I'm afraid the performances issues won't disappear.