Similar flexure beam design, but different simulation result

Dear all,

I am doing simulation of two beam structure based stage, but the simulation result is different from the beam theory design. Can anyone tell me what result this difference?

I test two designs, the basic beams have the same dimension:

l=60 mm

t=1.1mm

w=25.4 mm,

The designed deflection at Force 20 N should be around 1 mm.

The simulation result of double folded beams stage is quite the same with the theoretical result. But the simulation result of the other one, double folded beams stage--flexure Y, is only half of the theoretical result.

I think the two stage should have the same deflection result under this situation. I do not know which part is wrong.

Thank you very much!

best

SolidworksSimulation