Samazar wrote Just to understand, once a satellite unit has been added wirelessely and then hard-wired to the master unit - does it automatically resort to the wired connection when it is used by a...

@orangepants Satellite Deco that is wired to the home network should deliver same speeds as Main Deco, if everything is right. If you are not getting anything near Main Deco speeds when your mobile...

@Samazar I think both options are equal: connect everything to switch, and switch to Main Deco, or connect some devices to switch and connect one of devices to Main Deco. This question was not raised...

@CUK0724 Choose TP-Link brand and those adapters from it that have single Ethernet port. Powerline adapters with Multiple Ethernet ports have less chances to be compatible. Make sure you buy...

@qwrty_ftw Check the following TP-Link Deco FAQ, section "Q3: Which switch models support Ethernet backhaul?": General questions about Ethernet Backhaul feature on your Deco

@HuanitaG That looks like an issue with Ethernet cable connecting Main Deco to ISP modem/router. It is possible Main Deco renegotiated 100Mbps speed instead of gigabit. Unplug that Ethernet cable...