Hey Trace I just had this problem . After several youtube videos that didnt help at all, I found the solution.
I toke apart the controller and actually carefully push the housing unit of the bumper switch toward its respective button and it worked. I dont really know why but it does. I had up my pcsx2 emulator, to test the button functions in the control mapping. I kept the back of the controller attached and just took off the face. This way you can put the battery back in and while the controller is running (and with the mapping test on the emulator) open you can carefully press against the housing unit until you see that it is functioning properly. Good luck to you man hope it all works out,