Try Tools | Check | Sum Forces to confirm that the applied force/pressure load is in the direction that you think. Look in the analysis .f06 file for the SPCFORCE resultant (near the bottom of the file) and confirm that these are equal and opposite your intended applied load (including gravity, if any). SPCFORCE Resultant is the vector sum of all reaction forces/moments. Gravity is not reported in Tools | Check | Sum Forces, so make sure (if you have switched it on) that it is the right direction.
Also, make sure (eg. via F5 -> Deformed and Contour), that you are looking at the deformation of "total translation" not one of the components. If it is one of the components, Femap cannot really make sense of that as a proper deformation plot, which needs X,Y,Z vector components of deflection.
Or use List | Output | Results to Data Table to show a listing of X,Y,Z deflection of some midspan nodes to confirm or refute what you expect.
Also, if you run an analysis multiple times, it stores the results each time, but does not automatically show you the last set, so make sure you are looking at the latest set of results.
If you are using actual beam elements and the result view you have chosen is "beam diagram", this is normally shown in the local Y-axis of the beam element.
Between these, I suspect you will identify why it appears not as expected.