We solved it by hand. Explanation : when you want to edit photo on an NLE to make a diaporama, it's sometimes hard to handle very high resolution like 5k (if we had animation effects etc.). So we generated smaller files from RAW in jpg (smaller than 2k). But contrary to video, there is no relation between the two files in the metadatas. In video, we have timecode for example. So when we do the conformation, Resolve is unable to conform just with name file, even when you change the extension ".jpg, .raw".
The only solution is to edit online, but we didn't have enough power with the machine. I have another fiction project to manage that is all in photography and we decided to use a high end machine and Resolve. We are also experimenting with the silent picture option to save time.