This is a followup to discussion on incorrect Shutter Speed being reported. Yes, I'm a bit of "dog with a bone" on this 😉
Further research on the EXIFTOOL COMPOSITE: SHUTTER SPEED shows it's dervied from 3 different other tags including EXPOSURE TIME.
There seem to be differences between what Shutter Speed and Exposure Time means and recored. Exposure is in seconds and Shutter is in some other unit which can be converted to seconds. There is also consideration for step-less shutter speed which I found a reference to and am not familiar with.
So, from examing a sample CR3 (OP used CR3) file, here are the related tags reported from EXIFTOOL
[EXIF] Shutter Speed Value : 1/49 [Composite] Shutter Speed : 1/50 [MakerNotes] Target Exposure Time : 1/51 [EXIF] Exposure Time : 1/50
In LrC, the EXIF reference is to EXPOSURE in time and aperature which seems to imply it's using the Exposure Time. When I load the sample CR3 into LrC 12.0.1 it shows under EXIF Exposure 1/50. It shows 1/50 under the Histogram.
"Stepless shutter speeds have been around since mechanical shutters have been controlled electronically. My old Minolta XD-11 manual talks about when in Aperture Prefered the shutter is stepless even though the display in the camera viewfinder is stepped. This is the same way it is now. The camera is displaying 1/60 for shutter speed but is using a stepless shutter speed. I for one do not want to see an oddball shutter speed of 1/64 or such in camera or in LrC. It really makes no difference except for maybe some scientific purpose and they would not be relying on the camera for the data anyway.
Edit: The shutter speeds do match. LrC EXIF for RAW shows the same speed as the exported JPG.