Problem about the 3-D truss bridge model compared with the 2-D simplified model

Can anyone quickly glance my model to give me some advice.

I put a simplified 2D truss and 3D truss model by STAAD PRO together. The top chord and vertical members conform well. But the lower chord and transverse forces in the middle three panels, 3D result is about -60 kip(Load case: Dead Load+ Future wearing load); 2D result is about -130kip (Load case: Dead load+ Linear load for 2D truss). I don't know why the load path is different even under the same configuration of these two models. And also, you can see the MomentZ at exterior stringer (logitudinal floor beam) is greater than interior ones. The common sense told us the interior should take more load than exterior, right? I am not sure about this 3D model, the load applied should be same on these two different models here. I disappropoitly put two models in the same file just for clearly comparison. Check to see if you can find some clue. Thanks a lot.

Structure2 with pinned connections.std