Analyzer House.stdstaad BM.pdf
Hello,
In your model for load case 2 the loading on 2 sides has difference and that is causing the change in pattern of bending moment.
If you use 2.47kN instead of 1.26kN on both side you will get similar bending moment.
Apart from that you will notice a huge amount of displacement in your model which is not expected. Please review the displacement diagram and values and make necessary adjustments in the boundary condition.