I believe this is Activisions doing, and not a fault from netduma
I do not have a netduma router (still waiting for it to arrive), however I use a VPN to connect to different servers away from UK
My VPN provider has a server called AUS1 (Australia). When connected via VPN, the Warzone geo location in settings shows "New South Wales" and I always get put into the Chile server with other South Americans.
My USA/Canada friends get around 80 ping in this lobby with me, so it seems to definitely be connecting to Chile (or somewhere close) rather than Australia.
I get 170 ping from UK (with AUS1 vpn connected)
It is something I do not tonally understand to be honest, but just thought I would add it