SUMMARY
My cameras are a Canon EOS 80D and a Canon EOS M6 Mark II, both of which are listed at digikam.org as a compatible cameras. I have .CR2 and.CR3 RAW files, respectively, taken with those cameras using a "Canon EF 100-400mm f/4.5-5.6L IS USM" lens. When the 80D and M6ii RAW files are viewed in Lightroom, BOTH display the lens model correctly. Likewise, ExifTool displays the correct lens model from each file. However, digiKam displays the lens model ONLY for the 80D RAW file. For the M6ii RAW file, it displays "Lens: unavailable". In fact, "Lens: unavailable" is always displayed for M6ii RAW files for every lens I have used, even those contained in the Lensfun files.

STEPS TO REPRODUCE
1. Display the Album list in digiKam
2. Find an album that contains a .CR3 RAW file from a Canon EOS M6 Mark II camera.
3. Select that RAW file.

OBSERVED RESULT
In Properties > Photographic Properties in the right panel, digiKam displays "Lens: unavailable".


EXPECTED RESULT
Properties > Photographic Properties should display "Lens: <lens model>".

SOFTWARE/OS VERSIONS
Windows: Windows 10 Home
macOS: 
Linux/KDE Plasma: 
(available in About System)
KDE Plasma Version: 
KDE Frameworks Version: 
Qt Version: 

ADDITIONAL INFORMATION