About two monthes ago I synced all of my photos to my OneDrive without any problems. Today all newly added photos are not stored as pictures anymore but as normal files. They can not be viewed in OneDrive online. Only downloaded.
I'm not sure I'm following as you didn't share too much.
An image is just a file with an extension.
Can you share an example of what you mean?
Can you upload a file with a debug log that shows the issue?
Can you share you rclone.conf without any secrets/keys?
I've analyzed the problem more deeply. It's up to OneDrive and not rclone. If I upload a photo by hand it's the same. As if OneDrive doesn't index the file. I can't add it to an album for example.
Sorry for the inconvenience. Rclone is great. Have a cup of coffee.
If you take a look at this table Overview of cloud storage systems you'll see Onedrive can only Read mime types. That means that Onedrive sets mimetypes itself either from the file extension or by sniffing the file or by magic - we don't know. Rclone can read these mime types (see rclone lsf for how).