@Takuiq Connection Preference feature is recommendation for device. Device does not have to follow it, and older devices often don't. Still, there might be something else with what you see and it...

@Takuiq 1) You only need to check in Deco app, under "Show List," to see if switch is supported. If switch supports Deco backhaul, all Satellite Deco connected to it will report Ethernet backhaul, if...

@bouncingboffin You can see in Deco app what type of backhaul Satellite Deco is using. In example I provided, Bedroom is on WiFi backhaul, while Study and Office are on Ethernet backhaul. Ethernet...

@Takuiq Answers to your questions: 1) Networking switch should be OK if it supports Deco Ethernet backhaul. Not all switches do, and for managed switches you might need to make additional...

@Kwiatek When this happens next time, check "Show Map" page of Deco app to see how Deco units connect to each other. Deco app may not update that info in real time, so first check "Show List" to see...

@ChrisJL_2005 It looks like you have found the culprit. Disable this in Synology NAS. Also, do you really need external access to your NAS? Because, if you don't, find UPnP setting in Deco app under...