Software Bug I believe. Wrong register contents.
I am using Nucleo - L412KB I think I might have encountered a Software bug. As you can see in the screenshot, the contents of the PWR_SCR in the SW don't match with the one in the reference manual. The contents of this register are probably swapped with PWR_SCR register and some bits are missing too.
PWR_SCR: Power Status Clear Register
PWR_SR1: Power Status Register



