When you use a NoActionBar, the status bar color is not affected by colorPrimaryVariant, so you have to use the older colorPrimaryDark.
I tried Light and DayNight NoActionBar. Both have the same issue.
This is somewhat intentional. Since by default status bars are assumed to be a relatively dark color (the status bar text and icons are light by default),colorPrimaryDark is semantically a better fit; whereas colorPrimaryVariant could either be lighter or darker than colorPrimary.
@dsn5ft I think it has no sense to keep using colorPrimaryDark if it is not appearing in Material Design guidelines. At least it should be added then in this page: https://material.io/design/color/#color-theme-creation

Would like to revive the issue. The problem still exists - just today spent ~40 minutes trying to find what is missing in my setup and why colorPrimaryVariant is ignored. Please update info on https://material.io/design/color/#color-theme-creation page.
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@dsn5ft I think it has no sense to keep using
colorPrimaryDarkif it is not appearing in Material Design guidelines. At least it should be added then in this page: https://material.io/design/color/#color-theme-creation