@FAHIM01 It's best to leave it on Auto Negotiation. Observe the negotiated speed here: If you see negotiated speed of a port that doesn't correspond to its actual bandwidth then you can select...

@wwwmagnottait Setup a hotspot on your mobile and use WDS feature of your C80 to connect to that hotspot:

@GavinEmberson If you're expanding your main router wireless coverage I would suggest to use X20 in AP mode to avoid double NAT in your local network. Try different wireless setting like WPA2 only =>...

@GavinEmberson Are you using your Deco X20 in AP mode ? What are your wireless settings for 2.4GHz channel ? You can post some screenshots here, just cover/blur your SSIDs and passwords for privacy.

hWmMzIfYNRISEgn wrote greetings, I would like to ask about few technical issues of ARCHER router AXE75 (as my local Czech tplink support failed to answer) are channels 12, 13 and 14(only in Japan)...

@GavinEmberson Perhaps this video could point you to the right troubleshooting direction.