Import problem regarding the combination of JPEG and RAW files on spezial file names

OK Guys, I have reset the preferences and tested several other things.

It looks like the underscores are not the problem, but the way or the place I am importing from:

If I use "DEVICES" (camera or card reader) in the import dialog, Lightroom is unable to treat JPG + RAW as one.

If I import from "FILES" (where Lightroom also shows the SD card), Lightroom shows the RAF (RAW-Files) only but copies the JPG too.

Can some Fujfilm owner try / confirm this?

Followup/Test

Ok, so I just tested, some points about the test:

• Windows 11, LrC 13.1
• In LrC, changed my setting for treatment of RAW and JPEG to Not separate. Restarted LrC
• In Camera (X-T5) verified that for Saving Data I selected sequential data save on cards
• In camera made sure I was shooting F+RAW
• In camera made sure for the raster I was saving as JPEG not HEIF (y the way, fairly sure LrC still does not directly support Fujifilm HEIF)
• In camera, RAW is not compressed (just saying)
• In Camera, default file name syntax is in use _DSFnnnn

Took a shot, then:

• On this Windows PC, used File Manger to copy the RAF and the JPEG to a hard drive, to a folder. I intentionally did not place them in a folder that my Test Catalog uses, just so when I used the Copy option it would have to actually copy, just in case.
• Brought up LrC selecting my Test Catalog (I keep a separate Test catalog for testing purposes)
• In LrC, selected Import, and selected COPY. Navigated to the folder I placed the photos in above.
• In LrC, I noticed that I could see one photo (as in the RAW and JPEG treated as one)
• Went for minimum previews, did not rename, did not use any presets.
• Clicked on Import.
• In LrC post import, I noticed I can see the photo (as one photo)
• In Windows File Explorer I can see the separate RAF and JPEG in the folder that the test catalog imported (copy) the images into.

I did not have the issue you brought up.

1. Inquiry

Curious as to why you want to treat these as one photo?

Also, do you shoot RAF+JPEG as to have better in camera previews, or do you want to be able to quickly share the JPEG prior to post processing the RAF?

Their are many reasons to shoot RAF (RAW) plus JPEG.

2. My workflow

I also have a Fujifilm, in my case an X-T5. This camera has dual slots. I am primarily a Landscape shooter. My workflow in camera is to shoot RAF plus JPEG, with RAF to slot 1, JPEG slot 2. In the Field I use the JPEG when reviewing post shot. And typically I have my Film Simulation set to a B&W if Landscape (think zone system) or Classic Chrome (I have no idea why, I just like it).

I do not bother (maybe I should) with changing the Data Save settings in camera as to drop that underscore. I have not had an issue with that.

Upon Import into LrC, I commonly copy the photos outside of LrC first then Import in LrC via Add (as to get those photos onto the computer ASAP) . AND I rename the photos after import (YYYMMDD_hhmmss).

Typically I do not import the JPEG files. Sometime in the case of a difficult shootI may just so I can quickly compare in camera processing with post processing if I am challenged. So, I do not see a bug with Set RaW and JPEG seperatly turned off and default Fuji file name as that is not my process. But I do not think the Fuji File names are the issue/cause.

3. LrC Preference file

The preference file contains more than the preference settings. Oh resetting it will change those back to defaults. But many more bits of info are stored in the preference file. When the preference file gets corrupt, odd things happen in LrC.

I can't explain why detection of pairs should fail just because of the underscore, provided the two are being imported within the same import batch. If in different batches, LrC will never detect such pairings AFAIK. And, I have heard that very large import batches can sometimes get processed as if they were separate batches. I don't think the sorting option seen in the import dialog has any bearing on that. So perhaps that overall import needs to be broken down into smaller successive chunks, selected under the appropriate sorting so that the respective Raw and JPG are both highlighted for each one. 

My stock response to this whole question of RAW+JPG - ignore as you wish, please - is: if you don't want to see JPGs separately inside LrC, why not set the camera to shoot Raw only? This saves space on the camera card and on the time taken for the camera to finish writing an exposure. If Raw-only is not available in the camera menu, one might deliberately import only the Raws. Either way import copying finishes more quickly; less imported-file storage space is needed; one is not left forever backing up extra data from which no benefit is being realised.

Starting the filename with an underscore if the camera is set to AdobeRGB has been commonplace for as long as digital cameras have existed. It is not special for Fujifilm cameras either; AFAIK all digital camera brands do this. It is an official standard. I can't check it because I am typing this on my iPad right now, but I find it very hard to believe that you would be the first one who encountered this. Have you tried resetting the preferences? 

https://www.lightroomqueen.com/how-do-i-reset-lightrooms-preferences/