A couple of questions. Do you have a custom camera profile applied via LR Desktop? For what type of photo/file type does this occur to you? - Guido
The camera profile is set to just the Adobe Standard. I did have to install the profile manually as it seems there was some issue with the Adobe Standard profile missing for my camera, a D810, on the latest update. The image files are imported and converted to DNG. As I previously mentioned, a preset is sometimes applied. Any modifications, even such as a change in crop, undo all changes to the photo made on the desktop side.
Could you send me an example photo plus one of your presets - best as a private message with a downloadable dropbox link.
In addition it would be great if you can provide Lr Desktop+Mobile diagnostig logs.
You can trigger the Lr Desktop log via Lr Desktop preferences -> Lightroom Mobile and when you hold down the alt key you will notice a generate diagnostic log button
The Lr Mobile app log can be triggered when you open up the settings and long press the top left LR Icon a diagnostic log will be generated and attached to your local mail client.