Cut and paste this URL to share the unmodified register and value:
https://regviz.com/r/STMicroelectronics/STM32L562/TIM15/SMCR#0x0
TIM15 slave mode control register
Slave mode selection
Trigger selection
Master/slave mode
Slave mode selection - bit 3
https://github.com/cmsis-svd/cmsis-svd-data