Arduino webclient unable to reach webserver on internal network

My router is on 192.168.178.1 and that address is not within the dhcp range (10-255)
I also tried to assign 192.168.178.9 to the Arduino, but that did not make any difference
There are no IP conflicts / no other devices claiming the same IP or double Mac addresses etc
I think it is a matter of routing on NAS side, but I just don’t know what? :confused: