A solution for macOS 14.5:
Get your interface name by ⌥-clicking the Wi-Fi icon and checking "Interface Name". Normally it's en0.
Disconnect from the Wi-Fi hotspot. Turning Wi-Fi off is not a solution; instead open the Wi-Fi menu and click the blue network to make it grey.
Run sudo ifconfig en0 ether 12:34:56:78:9a:bc in Terminal (en0 is the interface name from p1; use any MAC you want).
Connect back to the Wi-Fi hotspot.
The new MAC won't show anywhere in the UI nor in the networksetup -listallhardwareports output, but the router will see the new address. The address will reset when the device restarts.
Finesse
Users receive reputation points by contributing quality content to the forums.
Posts include post and replies published on the forums.
Post authors can mark replies as Accepted to indicate successful solutions.
Apple Developer Forums admins can mark replies as Apple Recommended to indicate an approved solution