New MOX, something rattled / was loose in the box

Opened it up (never used it yet, waiting for ISP) and found this piece of plastic falling out when I tilted the device.

What is it? Where does it belong? Is it a problem that it fell out?

Looks like a cover… for aesthetic purposes I guess… do you have particular modules ordered with your MOX? Your plastic bit could be PCIe

It’s a classic preset. You mean that’s the cover that’s equivalent to the “If you don’t use this hdmi port, leave this plug to keep it from collecting dust”?

Worth opening the thing up and replacing it or is it a “Aww, nvm” thing?

plug it back, it’s actually important to avoid the system trying to access moxtet bus, when there is no other module attached