@TheProphet I am going to start with basics of how WiFi mesh system operates, with specifics for your house. These are applicable to Deco and to any other brand of WiFi mesh. Each WiFi mesh node has...

@TheProphet I think I can help you with that, but I need you to clarify few things for me first: This is two floors house, the first floor plan is on the left of that image and second floor plan is...

@Beungeut The first test should be to check if it is hardware problem. Switch second floor Satellite Deco with the first floor Satellite Deco, see if problem stays on the second floor (not hardware...

@Nardol For WiFi mesh, a bit of interference is necessary. If your smartphone does not see signal from more than one WiFi mesh node, it can't switch seamlessly between nodes when you walk in your...

@WHE77ON You said you've got five Deco M4, but your diagram shows just four. Keeping fifth one as a spare, perhaps? If yes, it may come handy. Satellite Deco units prefer to connect to Main Deco...

@Nardol I would not call four Deco M5 in the three floors house "too many." See How many Deco units can I add to my Deco mesh network? There could be multiple reasons for disconnects, for example:...