The change from iPhoto to Photos is a change made by Apple. After this change, unfortunately your images can be displayed in random order.
Our program keeps the same order as the Photos app. You can change the order of your images by following the steps below:
1. Open Photos.
2. Click on the "Darstellung" tab in the top left
3. Click on '"Automatisch nach Hinzufügungsdatum sortieren'.
4. Stop and restart the editor.