Cut and paste this URL to share the unmodified register and value:
https://regviz.com/r/stm32/stm32c0/STM32C011/TIM14/TIM14_TISEL#0x0
TI1SEL=B_0x0
TIM14 timer input selection register
selects TI1[0] to TI1[15] input Others: Reserved
0 (B_0x0): TIM14_CH1 input
1 (B_0x1): RTC CLK
2 (B_0x2): HSE/32
3 (B_0x3): MCO
4 (B_0x4): MCO2
https://github.com/modm-io/cmsis-svd-stm32