That's an SMD resistor, which seems to be on the top right VRM phase, one of the SOC VCC phases.
You should definitely solder that on again, or have it soldered on again. Right in the center of your circle is where it came from. I don't know if you can RMA the board, because you caused this yourself (which is usually not covered). You can see that around it, there's a couple solder pad pairs left empty, so MSI continued to optimize the design to leave out all unnecessary SMD (surface-mounted device) components. If we turn that thought around, all SMDs that are left will have an important function.