@matmatician 

The info we got from HQ is that Deco M9 supports band bonding as there are 20/40/80 GHz band for 5G. And Deco the will choose one of them depending on the congestion of the wireless environment. The more crowded the wireless environment is, the smaller bandwidth the Deco M9 will use.

We do have a beta program that you can sign up for which encompass a variety of products including the AX series. You can sign up to be a potential tester here: https://docs.google.com/forms/d/e/1FAIpQLSdbZUXnbcUr9KqU9JufznPb0_fsbrHGDvXUsR6ObJYhMpfBeg/viewform

What do you mean by channel bonding?

As in what in the image you posted makes you think that channel bonding is not working?

There is no way you are getting 260Mb from a 20MHz channel. Looking at the specs it seems the M9 has two spatial streams so the maximum air interface rate for a 20MHz channel would be 173Mb.

MCS charts give air interface rates which do not correspond to real world throughput. A good rule of thumb is to divide the air interface rate by two so to get 260Mb your air interface rate is likely over 500Mb.

I believe you are reading the graph incorrectly. The x-axis of the graph are channel numbers not frequencies. The program is clearly stating that the bandwidth is 80MHz which is comprised of four bonded 20MHz channels. The only peculiar thing I can see is that the program is not reporting one of the standard 80MHz channels. It seems to be saying that you are using 44 which is not the beginning or centre channel of a standard 80MHz bond. This could be a software reporting issue though. LinSSID doesn't seem to be the most up to date software around.

If you have access to an Android device I can recommend WiFi analyzer. It will display the channels used, the corresponding frequencies and the current air interface rate.

netspot is also useful for Windows and Mac machines.