Cut and paste this URL to share the unmodified register and value:
https://regviz.com/r/stm32/stm32f4/STM32F410/SYSCFG/CFGR#0x0
Configuration register
FMPI2C1_SCL
FMPI2C1_SDA
https://github.com/modm-io/cmsis-svd-stm32