Cut and paste this URL to share the unmodified register and value:
https://regviz.com/r/stm32/stm32h7/STM32H745_CM4/SYSCFG/UR15#0x0
SYSCFG user register 15
D2 Stop Reset
Freeze independent watchdog in Standby mode
https://github.com/modm-io/cmsis-svd-stm32