I shoot Fuji rafs (X-T2) and convert these to jpegs using ON1 Photo Raw.
When I view the jpeg in Photo Mechanic, the IPTC data often (but not always) shows the Capture Time as the Create Time of the jpeg, not the Capture Time of the raw. But when I view the jpeg IPTC data in ON1 it shows the correct Capture Time. The jpeg EXIF as shown in Exiftool is correct.
Because this problem does not arise every time it is hard to find a solution.
I have also had this problem when using Photo Ninja.