@David-TP 

Great news. I hope that it will arrive soon. BR

Tracked down a problem with ipv6 and my deco x90s down to MTU (I think as well). IPv4 works, IPv6 leads to unstable connection and decos loosing their connection.

Disabling v6 made all those problems disappear, but I think the deeper issue is MTU settings.

Looking forward to getitng this feature.

I hope this feature will be available for Deco M5 as well. I am using a Deco M5 router, which is also connected to an optical network provider using PPPoE. The MTU which is set by default on the Deco M5 is not the correct MTU for my connection, and that makes a lot of websites load slowly or become totally unavailable, without the use of things such as a VPN. I really hope you can add the tiny setting of choosing the MTU size on the Deco M5.

Update: I connected my laptop directly to the ISP using the Ethernet port, and using dial-up I managed to set up PPPoE on Windows 10. Then, I was able to connect to all websites and the problem of some websites loading extremely slowly went away. I opened the Command Prompt and used the command netsh interface ipv4 show subinterfaces and saw that the MTU of the dial-up connection was automatically set to 1480 (unliked Deco's default, which I assume is 1500), and I think that's what solved it. Using the command netsh interface ipv4 set subinterface "My Dialup Adapter" mtu=1480 store=persistent I was able to change the MTU to different sizes, but I've seen that for this network adapter, Windows 10 doesn't allow me to change the MTU to more than 1480, but I could set it to lower values (while other network adapters were on 1500).

  @David-TP Can I install the Deco X20 V2 firmware on a Deco X20 V4 hardware? I need to change the MTU size, so I have to buy a different model than the Deco M5 which I currently have (and a software update is not available for). I'm trying to buy a model which supports manual MTU size selection, and I found the Deco X20, but it is V4 and not V2, and I hope it is ok for me.

Edit: Also, is there a forecast of when the manual MTU size selection update will be available as a non-beta version for the Deco X20 V4 or as a beta version for the Deco M5?

  @David-TP Great news there are these betas for some routers, but unfortunately my X20s are v1 and v4, not v2. Still hope the final version will arrive soon. Meanwhile I have to run 2 concurrent WIFI networks at home as my current DECO's network can not support all of my devices :(

  @David-TP Any news why the beta FW is available for X20 v2 (which I do not have) but not for v1 or v4 (which I both have, 2 pieces of each)?