Shift key not working? Part 2
Almost five years ago, I ran across an issue where the SHIFT key was not working as expected, specifically when trying to "hot grip" multiple grips. At the time, I found that Raster Design had hijacked the shift key to allow for image selection.
Well recently I ran into the same issue in Civil 3D, except that I don't have Raster Design installed in this case. After a little searching around, I found the answer in a comment to the original post from someone identified as "mmyers". The solution is to run the MAPIOPTIONS command, which includes the same toggle named "Shift+Left Click Image Select". Disable this toggle.
If you choose to leave this toggle enabled because you need to be able to select images this way, then you can FREEZE the layer on which the image is inserted in order to use the Shift+Left Click for grips. Simply unloading the image has no effect, which can confuse you even more since the image is not visible but the effect is still happening.