Cut and paste this URL to share the unmodified register and value:
https://regviz.com/r/stm32/stm32u5/STM32U535/ADF1/ADF_BSMX0CR#0x0
ADF bitstream matrix control register 0
Bitstream selection
BSMX active flag
https://github.com/modm-io/cmsis-svd-stm32