Port Forwarding Limitations

To start my router is the Nighthawk Tri-Band AX8 RAX70 (I couldn't find the model in the categories above) firmware version: V1.0.3.92

I'm having some issues with trying to use the port forwarding under the advance options in the router. I'm playing a game that requires a:

TCP: 25,80,110,443,50000-65535

UDP: 50000-65535

however this nighthawk only goes up to 65534 and throws an error if I try to exceed it when i apply the settings. Is there any way to get the nighthawk to use this port? 

If thats not possible am I able to extend the DHCP lease to 72 hours instead of 24? 

Thanks!