DELL Precision 3520 powers on automatically

[Rekoo1997]

Laptop Model: DELL Precision 3520 Motherboard: CDP80 LA-E152P Rev 1.0 (A00)
Issue: The laptop powers on automatically after being shut down.
Actions Taken by Technician:

BIOS reflashed

Intel ME region cleared
Result: Issue still persists
Additional Observations:

Power button reads 3.3V (normal)

The problem occurs both when running on battery and when connected to AC adapter

[mon2]

If removable, remove the WIFI card and test again. Perhaps waking up due to the PCIe wake line.

[Rekoo1997]

If removable, remove the WIFI card and test again. Perhaps waking up due to the PCIe wake line.

I already removed the Wi-Fi card, but the same problem persists

"I also removed the screen flex cable, the keyboard, and the touchpad, but the same problem persists.

[mon2]

Does the laptop behave properly if powered by only the adapter or only the battery?

[Rekoo1997]

Does the laptop behave properly if powered by only the adapter or only the battery?

"The problem occurs when operating on battery only, when operating on charger only, and even when both are connected — in all cases."

[mon2]

Check your LID settings in the BIOS. The unit can be made to power on if the LID is open.

[Rekoo1997]

Check your LID settings in the BIOS. The unit can be made to power on if the LID is open.

I have already checked the LID settings and also tested the sensor, but the same problem persists.