When I received my RunCam2, it sounds like something inside of the camera is loose. What I should do?

Pls open the case firstly, then you will see a tin shield like this:

If it's this part which is loose, don't worry, you can put it back by yourself.

You will see some small buckles on the PCB like I've circled in this picture:

And then you can put the shield back. It should be like this at last: