Cut and paste this URL to share the unmodified register and value:
https://regviz.com/r/stm32/stm32h7/STM32H723/FDCAN1/FDCAN_TOCC#0x0
FDCAN Timeout Counter Configuration Register
Enable Timeout Counter
Timeout Select
Timeout Period
https://github.com/modm-io/cmsis-svd-stm32