On what device are you trying to "save" your work? It shouldn't be necessary to do that. Any adjustments made using Lightroom, either on the computer or on any device are automatically applied and should be automatically applied to any device that is synchronized. The only time it is necessary to "save" an image is when you want to create a copy of that image that includes all of the adjustments. Otherwise, the image is displayed with the adjustments applied by Lightroom.