You have to shoot uncompressed RAW, and you have to be up to date with the operating system. RAW file handling is handled by Apple, and that's all they support.
I'm not a Lightroom user, but I believe Lightroom has its own RAW file support. If you have compressed RAW files, try installing the Lightroom app and then opening the files.
Apologies, some of this may be wrong, I'm not an expert. But 100% Apple natively supports only uncompressed RAW files from Fuji.