Wake-up over LAN

By sending so-called the Magic Packet, I'm trying to wake-up a PC over LAN - no luck.

Target PC BIOS settings: Power Management > Wake on LAN: LAN only. Target PC NIC settings: Power Management > Allow this device to wake the computer CHECKED. Target PC NIC settings: Power Management > Only allow a magic packet to wake the computer CHECKED. Target PC NIC settings: Advanced > System Idle Power Saver - DISABLED. Target PC NIC settings: Advanced > Wake on Magic Packed - ENABLED. Target PC NIC settings: Advanced > Wake on Pattern Match - ENABLED.

The packet does arrive at destination; tried ports 0,1,7,9. What else should I be looking at?

Solution

The problem turned out to be windows updater - it was constantly running some kinda super setup to unsuccessfully install the 20H2 update and that was an infinite loop of try-and-fail. Killing that setup in task manager and disabling automatic updates solved the problem. Further investigation proved the faulty setup did not allow PC to go into S0 power mode, but its NIC (and BIOS) has firmware to perform WoL from S0 only. Note: both, motherboard and BIOS are proprietary so I can't add anything else about the system but my frustration with DELL.