I have exactly the same problem, of course with DELL - all other notebooks I use (HP, Lenovo, Asus) do NOT have such problem. I've spent a few days now and lost a lot of time and nerves - it just sucks, after the latest Win10 update, the bloody DELL precision cannot sleep, as of the idiotic "Standby (S0 Low Power Idle) Network Connected" and "Standby (S3) This standby state is disabled when S0 low power idle is supported." The only solution: I'll never buy another DELL again. "S0" should be called "DELL Insomnia" really, as it keeps the notebook running, going overheated and draining the battery empty - it's pretty dangerous if this happens in a closed backback, it could burn as it's overheated as hell in the sommer.