There can be 2 reasons why this might happen:
1) The versions could be different. The calculation algorithm are updated which may lead to minor difference, though nothing major.
2) Installation related issue. In past we have seen case where the user faced certain errors in installation, but ignored it and used midas. The moving load results were different for same model.
Kindly reinstall midas Civil on the system with unexpected results. If that doesn't resolve the issue, kindly share the model file and the exact build of midas Civil with build date for further review at our end.