Cut and paste this URL to share the unmodified register and value:
https://regviz.com/r/STMicroelectronics/STM32U599/SYSCFG/CSLOCKR#0x0
SYSCFG CPU secure lock register
LOCKSVTAIRCR
LOCKSMPU
LOCKSAU
https://github.com/cmsis-svd/cmsis-svd-data