@David-TP Yes, that is the network layout that I used. I have tested multiple times, also in different days. I tested both by using WiFi and by using a network cable to connect to the 2nd Deco XE75....

I also tested by connecting one of the Deco X60's to the wired Ethernet backhaul and the Deco X60 reaches close to 1 Gbps upload speed. So I guess there's likely a bug in the Deco XE75 firmware...

I have a mesh wifi system composed of 2 Deco XE75 and 3 Deco X60. The main Deco is an XE75, the other XE75 is connected by ethernet to the first one and the 3 Deco X60 are using the wireless...

It seems that there's no way to disable the ipv6 firewall on Deco XE75 and all the incoming connections to delegated ipv6 clients in the internal network get blocked. Adding ipv6 firewall rules does...