@Bigredm20 If your powerline adapters are compatible with Deco Ethernet backhaul, you can use them to link Deco in the summerhouse to Deco in the house and that will bring Deco mesh with powerline...

@MattS666 It is possible that Ethernet cable you are using is not recognized by Deco, or ISP router is not compatible with Deco Ethernet backhaul. You can test both: 1. Take Office Deco to the room...

@MattS666 For what you want to achieve, you need to switch Deco mesh to Access Point mode: Switching a Deco to Access Point (AP) Mode

@PWH Firmware 1.4.* does not have Connection Preference feature, it comes with 1.6. It is not guaranteed firmware 1.6 will be released for Deco S7. Powerline adapters are the last resort for wired...

@DrAhmed86 I want to be sure your Pixel connects to hardwired Main Deco and does not go through WiFi connected Satellite Deco. This is the simplest way to ensure it. Also, trying different speed test...

@DrAhmed86 OK, then please do the speed test with the following setup: 1. Power off Hallway Deco. 2. Bring Pixel to where Living Room Deco is, place Pixel in direct unobstructed view from Main Deco...