What i had to do was make sure any (if any) extra settings on the modem arent enabled or firewall set too high. Then for the R3 settings I went to Settings > DHCP > Add Rule > Select Xbox/PS5/PC from the list > Reserve IP. Then i went into Port Forwarding > Add DMZ Device > Select Xbox/PS5/PC from list > Save. Also disable ipv6 in WAN and LAN as mentioned above. Once you have done all this reboot the R3 as well as your gaming device and then check for open nat type. It worked for me and ive been enjoying the R3 since, yes it has minor gripes here and there for me, but for what i need it to do which is Open NAT and Geo Filter my PS5 and give me the lowest latency possible while mitigating bufferbloat it has worked exceptionally well. Hope this helps you bro.