You‘re right, the firmware files are not zipped.
https://fujifilm-x.com/global/support/download/procedure-x-interchangeable-ver2/
I‘m pretty sure this was different some time ago bit I might remember falsely.
Is it a new camera and did the issue exist from the beginning? Then you should contact your dealer. You“ll find other ressources for your country on the Fujifilm website.
Perhaps the focus mode switch is defective. Or the camera has problems detecting the lenses correctly due to dirty contacts. And make sure that the lenses are completely attached (click noise).
In this case it‘s most probably just a part‘s name. You would need a service manual to look parts up, but these are not publicly available as far as i know.