Why the large screw for the camera ball head is loose and freely rotates? Is it defective?

Please do not worry, this screw is designed like this.

It is a 3/8 screw and is not fixed to the NOMAD plate, so it is normal that it looks loose and freely rotates.

For how to use it, please unscrew the middle red ring to take out this whole plate, attach a ball head to it by screwing this 3/8 screw tightly. At last using the Allen Key to screw the small set screw/pin to let this attachment tighter.

Please check the simple setup video guide here: https://drive.google.com/file/d/18epOp5qvmJWiziOmrFgwaUaM08n2gaF7/view?usp=sharing