I have the Deco X20 3-pack and have been struggling with very slow wifi speeds. My original ISP router in one location was often faster.

The Deco X20's are in AP mode using both 2.4GHz and 5GHz.

I have tried locating them at several locations around the house to get the best speeds.

1) both the secondary X20's ALWAYS connect back to the Main X20 which is ethernet connected to the modem/router of the ISP.

2) In the latest locations I have used, I placed one in the basement (main, ethernet connected), one on the first floor and one on the second floor where my wife has her office and a desktop machine.

Using the app, I discovered at first that the desktop machine on the 2nd floor, despite having an X20 in the same room would connect to the X20 on the first floor. This morning, I have looked at the app and the desktop machine on the 2nd floor is now connecting to the X20 in the basement. The desktop machine is completely bypassing the X20's on the same floor and one below.

I am really not sure what the point is of having the extra X20's or mesh is!