I have the existing setup below:

4F Internet -> Deco M5 (main Deco)

3F Deco M5 (ethernet backhaul)

4F hallway Deco M9 (ethernet backhaul) -> 4F room Deco M9 (wireless mesh)

I recently got interested in locally streaming games from my desktop PC, so I decided to replace the 4F hallway M9 to a Deco X60, as I was hoping to for my wifi 6 capable devices (Legion Go, Odin 2, Iphone 15 etc) to have wifi 6 speeds on the local network however I am only getting WiFi 5 (866mbps) speeds on all these devices. 

Things I tried which did not work: 

1. Firmware upgrades
2. "force" Wifi 6 on the devices
3. Turn off fast roaming/beamforming
4. Reboot the whole deco network 

Note that I can see the devices connected to the 4F room of which is the only location I use the devices.

Any advice how I can be able to connect my devices to use WiFi 6?