Hyper-V: NAT not functioning / guest cannot access internet
Solution 1:
But in an attempt to prevent the VM's IP address from changing on each reboot, I attempted to create a new virtual switch and set up a static IP address with NAT
This is an improper use of NAT in Hyper-V or any other like App such as VMware.
NAT is for DHCP and IP addresses will change occasionally.
If you wish to have a Static IP address, you can set up an External Network Switch in Hyper-V (so Bridged Network) and then the Guest will get an IP on the Host Network Router. That can be Static if you wish.
I have tested this on Windows 11 Pro, Hyper-V, and a Linux Guest.