I tried the things that were suggested in this thread but I still can't wake the PC using the keyboard.
Win10 is the latest 20H2, mouse/keyboard connected using wired USB directly (no bluetooth or hub).
The bios setting for power management is "OS" which greys out the bios settings.

Fast startup is disabled. Balanced power setting with hybrid sleep enabled and hibernate off, wake timers enabled.

Output from "powercfg /devicequery wake_armed" shows wake from keyboard is enabled.
HID Keyboard Device
HID Keyboard Device (001)
Realtek PCIe GbE Family Controller #2
HID Keyboard Device (003)

Any ideas?