The Sort Order In Photos Is Wrong?

Hi
I have a problem with the sort order in Photos.
After a holiday in New Zealand and Australia I have loads of photos taken with two iPhones and a Nikon D7200, and want to manage them in Photos.
I use iCloud Photo Library, so photos taken with my iPhone Xs Max is automatically uploaded. My wife’s iPhone 6s’s photos are transferred to my MacBook Pro by cable, and photos taken with my DSLR is imported via the card reader.
The two iPhone’s photos are in right order, but the DSLR photos are not in right order. They are in correct date order, but the time order is more random. Sometimes just scattered in between the iPhone photos, and sometimes in a “block” after iPhone photos. So for example the same mountain photographed by both iPhone and DSLR will turn up different placed in the Moments tab.
I have checked right time is set in camera (checked EXIF info).
I use the Moments/Collections/Year section of Photos. I know the All Photos section is sorted by time ADDED.
…
—–
Morten dk