@RedRoger Actually, there is a state when the Deco in AP and a main routeur with DHCP work fine together. But if either of them goes offline then back up, the deco "smart dhcp" fires up and messes...

Exact same issue today, first day with a 3-set of Deco X60.. A pure nightmare with the Deco DHCP taking over the main DHCP (on the actual router). It's totally crazy and irresponsible to do...