Hi Roberto, would be great if you can attach a screenshot and in addition to let us know which raw file type you are using.
Am I right that you have the most recent Lr Mobile app version running?
Guido/ Lr Mobile QE
I'm using .cr2 raw file from a Canon 5d mark III and all my apps are updated to latest version.
I shot tethered from a macbook pro laptop, then imported the collection from my iMac selecting the iMac catalog as main catalog. The images that have the problem have been shot with self rotation off in the camera, then I turned them left or right as needed in LR from the laptop.