I found the problem! It was Steam running in the background. I killed Steam, and my computer now sleeps like a baby.

Yes, in my furious search for a solution, I have come across dozens of posts like that. However, their problem is quite different from mine.
My computer doesn't randomly wake up from sleep. When it...

Thank you for your suggestions!
However, I don't believe this to be a practicable approach, given that my problem is not reliably reproducible. In the worst case, I would have to spend 2-3...

OS: Windows 10, version 20H2
CPU: AMD Ryzen 5 3600
Board: MSI B450M PRO-M2 MAX (MS-7B84)
Video card: nvidia GeForce RTX 2060

My desktop PC often shuts down when I tell it to sleep. It happens...