Last week we found a bug in the Layout dealing with the “Preserve Scale” function of the Sketchup Model Viewport. The work around that I found works is to toggle on and off the “Ortho” button and then set your viewport scale to the desired scale. After this happens you are given an option to “Reset” your camera, do not hit reset or the camera will randomly move again. Now you should be able to change scenes without having the camera move randomly. Hope this helps 
