@AzizaC What you need is "5-port gigabit Ethernet unmanaged switch" To avoid issues with Deco mesh, that networking switch should be of TP-Link brand. Any can do, check availability with local...

@David-TP I have submitted app logs and sent reply to your private message with ticket # under which these logs can be found. I have installed beta firmware you sent me on Satellite Deco unit I am...

@Andeh1 Unplug whatever is plugged to second Ethernet port of Main Deco, connect to it laptop instead and run speed tests on laptop wired to Main Deco. You can also repeat the same with each...

@Andeh1 It sounds like Main Deco having 100Mbps link speed to ISP router instead of gigabit. Is there an "Abnormal WAN speed" alert in Deco app?

@Andeh1 If that does not help, please clarify this: "Hardwired is fine at full speed everywhere" - hardwired through Main Deco or directly to ISP modem/router? Also, network diagram would by nice to...

@Andeh1 While keeping Deco mesh in Access Point mode, force Main Network to run on 5GHz only. You will find this option under WiFi Setting in Deco app: Also, try different speed test apps and sites....