Why is LT/RT triggers not working?

I have just recently did a thumb stick swap on the controller, and now the LT/RT triggers stopped working. I have absolutely no clue what is causing this. When I plugged it into gamepad tester, I then realized that the USB-C port stopped working without a battery, which was really weird. This problem seemed to have gone away. It could be due to a rumble motor wire disconnected, but that would not cause the problem, right? I do have a donor 1914 controller that I could borrow the LT/RT motherboard off of it, since it has really bad stick drift. I just want to know what I should do/try.