hi,

In our last flight we have experienced some uncommanded movements in the phantom we have never experienced before, about 40 cm in some random direction, I wonder if it could be a product of bad GPS coverage as we were in a river gorge. Thank you in advance for your answers.

Did it go into atti mode?

You can wonder and people can guess but unless you look at the recorded flight data, you won't know.

To get the data, go to http://www.phantomhelp.com/LogViewer/Upload/
Follow the instructions there to upload your flight record from your phone or tablet.
Come back and post a link to the report it shows you.

What were you flying?  Seems like you might have been feathering in and out of a satellite fix.  See link above.  

Sorry for the trouble. May I know which aircraft you are referring to? Also, is there an error message showing up on your app when that issue occur? If yes, please also send us a screenshot for further review. Thank you.