Hi Luisde,
Thank you for reaching out here at the Microsoft Community Forum.
We understand that the photos on your iOS device were converted to JPG and you are trying to find some setting to prevent from this happening. Let’s check on this together and find ways to address this matter.
In line with this behavior, this seems to be working as expected since the conversion of the files to JPG is automatically being implemented when the pictures are being uploaded to OneDrive and this may also apply to DMG files.
At this point, let me coordinate with our Internal Support Team to get accurate information if there’s an option to turn off this feature in OneDrive so you can stick the format of your photos when uploading on it. Once we have any updates, I’ll get back to you as soon as possible. Please standby.
Thank you.
Kind regards,
Genevieve