Cut and paste this URL to share the unmodified register and value:
https://regviz.com/r/stm32/stm32wb/STM32WB15_CM4/PWR/CR1#0x0
Power control register 1
Low-power mode selection for CPU1
Flash power down mode during LPRun for CPU1
Flash power down mode during LPsSleep for CPU1
Disable backup domain write protection
Low-power run
https://github.com/modm-io/cmsis-svd-stm32