@TiagoRocha Start with this document: Troubleshooting: Slow Internet Speed with Deco Devices

@Bizzyh87 Can you clarify what do you mean by "I cannot connect the NAS to the P9's and the PC?" To start with, on your network diagram NAS is connected to the Router, which is the right thing to do...

@AnFe Either way should work, but it may be easier to do initial Deco mesh configuration with Main Deco connected by Ethernet cable to the router.

@padraig TP-Link does not seem to offer power supplies. You can buy third-party power supply adapter with the following specs: 1. Output: 12V 1.2A. Note that amperage can be higher, i.e., 1.5A, 1.8A...

@yonz Let me start with saying that your case is unusual. Deco mesh prefers star topology. People complain on that forum that Satellites connect to Main Deco even when WiFi backhaul between them is...

@yonz It is possible your Deco B is too far from Main Deco to establish good link to it. Either that, or some sort of WiFi interference happens occasionally, such as microwave gets turned on or...