When I click on check symmetry and solidworks asks me to choose the part it doesn't let me choose the whole thing. It's a chassis made of pipes so when I click on one pipe and try to choose the rest after, it just points that pipe alone as the part I want to check the symmetry for and makes the rest of the body and the rest of the pipes invisible. And I tried multiple things to check all of them together at once and it didn't work like pressing ctrl and clicking or shading all of the body. Can it be some sort of malfunction in the program itself or some feature? I have the 2017 version.