When I search for photos taken by a particular lens, I get different names for the same lens. For instance, when I search for the Fuji 18-55, I get both "Fujifilm XF18-55..." and "XF 18-55...." I get different names for the same lens even on the same body.
Any idea what is happening and how to fix it?
I don't think you can fix this. Different cameras write different metadata, even for the same lens. Software may also play a part. Lightroom simply uses those metadata.
That's may be true but I'm getting the lens inconsistency even on the same body. The exif lens data is the same using a third party reader. The inconsistency is just in the Lightroom catalog.
Lens data are written to more than one field. Maybe that other reader is using another field that happens to be consistent, while Lightroom is reading a field that isn't. Like I said, Lightroom simply reads the data that the camera wrote. You would need a utility that can change these, Lightroom can't change it.
So I found if I deleted the photos from my library and re-imported them, the minority where the "Fujifilm" prefix was absent get imported with the "Fujifilm" prefix.
I was on the internet in the old days too where everyone just responded with "RTFM." So I get it. Any quirk is part of an intelligent design, and it's always the user's fault. And most of the time it probably is, but there is some quirk probably from an old version of Lightroom. Just leaving this here in case other people have the same issue and are called crazy.
Good to know that this (sometimes) fixes the problem. In case somebody reads this and wants to do the same, please note that deleting an image and then importing it again will reset all edits and wipe all added metadata like keywords!