rt-ax55 disables static IP communications when NAT is disabled

[Asusme1]

I am not using NAT so when I disable NAT to use the static IP's the router stop communications with the network. What would cause the router to stop after NAT is disabled?  It is running firmware version Firmware Version:3.0.0.4.386_52332

[jzchen]

What are these static IPs?  Are they assigned by your ISP?