I would assume this is due to the information being stored like that in the WMI. Try performing the following commands in CMD
- wmic path Win32_BaseBoard > lansweeperbaseboardwmi.txt
- wmic path Win32_ComputerSystem > lansweepercomputersystemwmi.txt
If the model is also "yyyyyyyyyyyyyyyyyyy" in the WMI classes, this is unfortunately not something that can be fixed by Lansweeper.