Was there any recent hardware or software changes?

Please run the on-board Dell Diagnostics and capture any error code or message.

No hardware change.

No error.

sh2sg,

Does it wake up when you press the power button?

Dell-Jesse L

sh2sg,

Following up with you on the system waking up.

Does it wake up when you press the power button?

The power button is assigned to Sleep, so yes, pressing power button does wake up screen.

Here's an article that should help. Try refreshing the hiberfil.sys file as suggested in the article and observe the machine.

sh2sg,

Click here for resolving the issue with the system.

I have hibernation disabled since day 1.

> powercfg /a
The following sleep states are available on this system:
    Standby (S0 Low Power Idle) Network Connected

The following sleep states are not available on this system:
    Standby (S1)
        The system firmware does not support this standby state.
        This standby state is disabled when S0 low power idle is supported.

    Standby (S2)
        The system firmware does not support this standby state.
        This standby state is disabled when S0 low power idle is supported.

    Standby (S3)
        This standby state is disabled when S0 low power idle is supported.

    Hibernate
        Hibernation has not been enabled.

    Hybrid Sleep
        Standby (S3) is not available.
        Hibernation is not available.
        The hypervisor does not support this standby state.

    Fast Startup
        Hibernation is not available.

That's the same article @DELL-Cares posted.It did not help.

I don't have hibernation enabled. I have latest Windows 10 updates and latest Video drivers, I have ran Windows Power Troubleshooter and System Files Checker scan, no issue was found.

I can't create new user account or reinstall OS.

And the most important fact, I can still wake up screen by closing and opening the lid, which doesn't seem to be the same case as that article described (can't wake up). To me, it looks like screen brightness issue as sometimes it was not completely black, a problematic sensor something?

I have sent you a direct message. Could you please reach out there?