Cut and paste this URL to share the unmodified register and value:
https://regviz.com/r/stm32/stm32f1/STM32F107/UART4/CR2#0x0
UART4 CR2
Address of the USART node
lin break detection length
LIN break detection interrupt enable
STOP bits
LIN mode enable
https://github.com/modm-io/cmsis-svd-stm32