Ansys Mechanical offers you an automatically calculated Display Scale Factor which is called Auto, Auto 0.5x and Auto 2x.  I choose one of those that looked good. If the Scale Factor is too large, the display looks bad, which is what you were initially observing.

I couldn’t solve your mesh because it exceeded the Student License Limits, so I had to use larger elements. However, I still wanted 4 linear elements through the facesheet thickness. I solved using Linear element order. I don’t know why your deformed shapes are so different to mine. There must be a significant difference because my mode 7 frequency was 13.7 kHz while yours was 392 Hz so your and my materials have a dramatically different stiffness or density or both.  Check what material was assigned to each layer.

If you have a physical test of a 3-point bending test, you will know the stiffness of the sample in lbf per inch of center deformation. You can build a model of the same test and tune the shear modulus until the model gives the same stiffness.