@David-TP

@EhDuh Are you getting any errors in the deco app when your trying to add the new deco? If so can you please attach screen shots

@EhDuh What color is the deco you are trying to add flashing? Are you trying to add it via Ethernet or WiFi? Try moving it closer to the main unit and see if that helps.

@intergram Beside trying the "Network Optimization" tool under the More tab you could try to reset both units by pressing the reset button on the bottom of each one for 2 seconds and then rebuild the...

@intergram Please try the following and get back to us. Go to MORE > QoS and ensure QoS is disabled. If you do not see an on/off switch for QoS, set it back to standard and remove all priority...

@intergram Have you tried replacing the cable? A bad cable can cause speed issues