A good way to troubleshoot incorrect sorting is to check the time metadata with the following exiftool command:
exiftool -a -G1 -s -api QuickTimeUTC=1 -Time:All -api RequestAll=2 image.jpg
Or to check all location metadata:
exiftool -a -G1 -s -n -ee -Location:All image.jpg
Or to check other metadata as well:
exiftool -a -G1 -s image.jpg
exiftool works best via the Terminal:
https://exiftool.org/
The link at the bottom has more info about installing and using exiftool.
There are some online tools that can also use exiftool to display the tags but none of those seem to display just the time info at a glance and they are not practical for large movie files. Below is one such web site but I'd recommend using exiftool via the Terminal instead:
https://exif.tools
GraphicConverter has exiftool built-in and it can also be used to easily display the metadata tags.
https://www.lemkesoft.de/en/products/graphicconverter/
The date of image files (.jpg and many others) should be in 'ExifIFD:DateTimeOriginal'.
But sometimes some apps get it wrong even if that most important date is correct. For example, I have had to fix the following errors that caused incorrect sorting in some Photos versions:
1. 'ExifIFD:DateTimeOriginal' was missing so the 'MacOS:FileCreateDate' or some other tag was used instead.
2. Mojave Photos.app 4.0, Catalina Photos.app 5.0 and Google photos show the time as 0.00.00 although it is correctly in 'ExifIFD:DateTimeOriginal'. The date is displayed and sorted correctly but such images are incorrectly sorted at midnight. Root of the problem was that 'IPTC:DateCreated' was present but 'IPTC:TimeCreated' was not or missing time in 'XMP-photoshop:DateCreated' if 'IPTCDigest is not current'.
3. GPS data and timezones and DST can mangle sorting. I had some vacation images abroad where Photos.app 4.0 displays the correct time but sorts incorrectly images that happen to have 'GPS:GPSTimeStamp' tag. That tag can be adjusted or deleted because it is not so important.
BTW, older iOS devices had 'GPS:GPSDateStamp and 'GPS:GPSTimeStamp' but in later iOS (after about iOS 13.2.2) the latter does not exist anymore and there is 'ExifIFD:OffsetTime*' instead. Some apps get confused about this.
4. It seems that in addition to a different timezone, the occasional 'GPS:GPSTimeStamp' or even if its seconds happen to have decimals between 59.996 to 59.999 (!) can cause incorrect sorting in macOS 11 Big Sur Photos.app (seems to be fixed in macOS 11.6.7 Big Sur):
https://medium.com/@lowply/how-to-fix-a-gps-time-stamp-bug-8d8d7584e004
https://photo.stackexchange.com/questions/77973/when-exactly-is-gpstimestamp
Photos grabs the date when importing so I re-import the files after fixing their metadata.
The dates in movies is another thing:
Movie dates and Photos.app - Apple Community