Lee
I've just gone back and looked at some X100F files from the original touch and try day back in 2017 - this is before I set up import profiles for my Fuji files - The RAW file has a color profile of Adobe Standard and a default sharpening set to 25, the corresponding JPG has a profile of 'Embedded' and a deafult sharpening of 0. But I don't know what would happen if lightroom has any default import profiles set up, do you have any? (I have a Fuji Import Profile that I made, that stes the sharpening of teh RAWs to 0 and sets the basic colour profile to Provia on import (Edit > Preferences menu)
There is JPG preview embedded in the RAW so thats how lightroom sees the initial Fuji profile in the RAF files.
I'm not sure how you are seeing the original sharper before you apply details, unless the act of editing (developing) the RAW it is taking it out of the embedded JPG image (which has the camera settings applied, and putting to basic lightroom import settings)
Are you have this issue on RAWs of JPGs (or both)