Cut and paste this URL to share the unmodified register and value:
https://regviz.com/r/stm32/stm32wl3/STM32WL33/MR_SUBG/AFC2_CONFIG#0x0
AFC2_CONFIG register
AFC Peak Detection leakage.
Select AFC mode:
Enable AFC.
Freeze AFC correction upon SYNC word detection
https://github.com/modm-io/cmsis-svd-stm32