Cut and paste this URL to share the unmodified register and value:
https://regviz.com/r/STMicroelectronics/STM32U599/SYSCFG/CFGR1#0x0
configuration register 1
I/O analog switch voltage booster enable
GPIO analog switch control voltage selection
PB6_FMP
PB7_FMP
PB8_FMP
PB9_FMP
ENDCAP
https://github.com/cmsis-svd/cmsis-svd-data