My issue is finally resolved after long days of troubleshooting.
SUBGHSPISD register was 0x00 on both boards, so that meant that the RF chip was never on.
I have no idea why this happened on both chip, I didn’t see this information anywhere on the wiki or in the docs, but those coming after me will have it.
(Thanks to this thread: Having issues enabling the SubGhzSPI on STM32WLE5J... - STMicroelectronics Community )