@fab1anch0 Sorry, I thought "both decos are connected with Ethernet cable" meant "both decos are connected to each other with Ethernet cable". What you have is much easier to test, and may not need...

@fab1anch0 This is not an expected outcome. In your network setup, you should be getting 300/300 on both Deco M5. Usually, in cases like that, the culprit is wired part of home network: cables,...

@maggieh You do not need to change router network name. Deco and router run separate independent WiFi networks. They can have different names. If you know how to turn off router WiFi, you can do...

@Celesteray If above does not help, find device with Ethernet port (laptop, desktop), connect it by Ethernet cable to "old" Main Deco, open http://192.168.68.1 in browser and see if you can get to...

@Celesteray It is possible your previous Main Deco still believes it is part of its own old WiFi mesh. See if resetting it would help. After you reset that Deco, you should be able to add it to your...

@MattJH There are two common scenario when Deco activates its own DHCP: Main Deco loses physical connection to the router, or Main Deco Internet health check fails. That health check is sending DNS...