Cut and paste this URL to share the unmodified register and value:
https://regviz.com/r/stm32/stm32h5/STM32H533/OTFDEC/OTFDEC_R3STARTADDR#0x0
OTFDEC region 3 start address register
Region AHB start address
https://github.com/modm-io/cmsis-svd-stm32