@Koeke This TP-Link FAQ document should help: General questions about Ethernet Backhaul feature on your Deco

@GyanAccessFreak You can add M5s to Deco mesh that runs on X55s. Check prices for X10s, if they are available in your region and for similar to M5 price, X10s are better addition. They support WiFi6,...

@ahmetm They have that feature, it is called Connection Preference. It is available for newer Deco models, also some older Deco models, but apparently not in Deco E4 that you have. Connection...

@Mattjtemp Just keep this setup, it is the best you can have for Deco mesh running in Access Point mode.

GyanAccessFreak wrote @Alexandre. X55 - 2 ports. https://www.tp-link.com/us/deco-mesh-wifi/product-family/deco-x55/ @GyanAccessFreak X55 has 3 ports. The link you provided shows 3 ports. Here is...

@Malco You can buy regular 5-port gigabit switch, connect it to master Deco P9 available Ethernet port and have 4 remaining switch ports to connect devices to. TP-Link brand of switch is recommended,...