@gandalf1369 Pay attention that in this scenario the device is still in router mode but it works as an AP. If you look at the diagram in the document the main router (white color) is connected to the...

@gandalf1369 There are certain situations (very rare) that this could happen: 1. When the router works as an AP or a wireless switch - details. 2. When hardware NAT (NAT Boost) is disabled -...

@vncz If the Deco is in router mode this could work but you should not connect to this switch anything else since that may cause a network loops. One more thing - don't use a D-Link switch for that...

@vncz When in router mode main Deco should be connected directly to the modem - details. When using ethernet backhaul you can refer this FAQ and read through this thread. If Deco is about to be used...

@M-collins_0929 Review your RE605X configuration. If nothing helps, I would recommend to reset the RE to its factory defaults and re-configure from scratch using this video guide. To reset the RE...

When building a mesh network with a range extender there's a known limitation that won't allow you to extend the main router guest and IoT networks through the RE.