Dell Precision T3600 Win 10 Shuts Down

I have a Dell Precision T3600 running Windows 10; all updates have been installed.

Control Panel Power Settings indicate the machine will sleep in 30 minutes - not shut down! :Smile:

Is there a BIOS setting I'm overlooking?

The machine runs fine, but I have a hard time believing there is a hardware issue. What would cause this to happen?

It seems to occur after a regular amount of time like it's shutting down on schedule.

Any suggestions?

Thanks.