Cut and paste this URL to share the unmodified register and value:
https://regviz.com/r/stm32/stm32l5/STM32L552/SYSCFG/CSLOCKR#0x0
SYSCFG CPU secure lock register
LOCKSVTAIRCR
LOCKSMPU
LOCKSAU
https://github.com/modm-io/cmsis-svd-stm32