Hi, NietRobijn,
Sorry to hear you're experiencing this issue.
A common cause for this problem is an outdated Bios version, check if you are running the latest version of the Bios. You can check which Bios version you are using on the System Information page.
1-Right-click on Start then click on Run
2-Type: msinfo32 and click on OK
3-Search for the Bios Version/Date
4-If you are using a version earlier than 1501, you can download the latest Bios version at this link.
https://www.asus.com/supportonly/strix%20z270f%...
Note: This is a non-Microsoft website. The page appears to be providing accurate, safe information. Watch out for ads on the site that may advertise products frequently classified as a PUP (Potentially Unwanted Products). Thoroughly research any product advertised on the site before you decide to download and install it.
Another possible culprit for this error is the Fast Startup setting, disabling it might fix the problem.
1-Right-click on Start then click on Run
2-Type: Control Panel and click on Ok
3-Click on System and Security
4-Click on "Change what the power buttons do" under the power option
5-Click on "Change settings that are currently unavailable", then uncheck the option "Turn on fast startup"
6-Click on Save changes and reboot your pc