Well that happens, started doing that a few days ago, I updated the bios to 1.3.0, the kionix freefall to 1.4.0, the drivers in general, the option of CPU performance is disabled. I did all the long tests of alienware assist support and all went well. I do not understand, I leave a video of what happens here below:
I did not see the drive light come on when you hit the power button. In BIOS, is the boot drive listed first in priority?
I took another look at your video and notice you were using sleep mode. My guess is that some app or program you are leaving open is causing the delay. Close all apps/programs and shut computer off. Restart normally and then go back into sleep mode. Wait a minute and then try coming back out of sleep mode and see if there is still a delay.
Are you using Firefox Browser?
Make sure to go through each BIOS update if you install them, installing the latest does not mean you get all the improvements from previous updates, each one is stand alone and needs to be installed to receive the benefits.
Try disabling fastboot in power options via control panel
hardware are quickly scanned during these bios screen. the fact it takes this long means there is some sort of hardware failure.