Dear Jan Csitkovits
Thanks for reaching out! Welcome to Microsoft Q&A. I'm Haien from Microsoft Q&A.
The incident is highly likely due to a mismatch, inconsistency, or latency in how the Microsoft Photos app on your specific laptop interprets the Date Taken metadata (EXIF data) embedded in the photos, particularly when combining files from different devices (Phone and DSLR). The issue is compounded by the OneDrive sync status and the app's indexing process.
Since you are using Windows 11, please consider trying my suggestions and keep me updated with anything news that you were trying:
- Settings > Apps > Installed apps > Photos > Advanced options > Repair. If it doesn't work, please click on Reset.
- Settings > Privacy & security > Searching Windows > Advanced Indexing Options > Advanced > Rebuild
- In File Explorer, right-click the folder with your photos > Properties > Customize tab > Select "Pictures" under "Optimize this folder for" > Apply.
- Also, in the same Properties page > Details tab > Check "Date taken." If inconsistent, open in Photos, right-click > File info > Edit the date/time to match. Do this for a sample from each camera to test.
For additional information about similar situation, please visit this article to know more: How to Organize Your Photos in Windows 11 | Microsoft Windows
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