Serial number for a computer and for a monitor are stored in different locations. The only way Lansweeper can do anything about it is if the data that is coming from the computers is scanned incorrectly.
If the computer stores the serial number incorrectly, there is not much we can do. For the monitor, you can check with the
monitorinfoview tool.
The serial number information for Windows assets is pulled from WMI class win32_computersystemproduct.
You can run the command below in CMD to check what the WMI has as data.
wmic path win32_computersystemproduct