Cut and paste this URL to share the unmodified register and value:
https://regviz.com/r/stm32/stm32wl3/STM32WL33/MR_SUBG/PA_REG#0x0
PA_REG register
FIR configuration:
Enable a ‘degeneration’ mode, which introduces a pre-distortion to linearize the power control curve.
https://github.com/modm-io/cmsis-svd-stm32