Cut and paste this URL to share the unmodified register and value:
https://regviz.com/r/stm32/stm32n6/STM32N645/RCC/RCC_APB1HLPENSR#0x0
RCC APB1H Sleep enable register
MDIOS sleep enable
FDCAN sleep enable
UCPD1 sleep enable
https://github.com/modm-io/cmsis-svd-stm32