Sir, I can't do the both because in my hand solution I have to make these changes then as well.
So if I decrease h which is the thickness of beam than also K will be changed and I'll got my fn=1.36hz
Also by adding mass I got 1.36hz, so my hand calculations will also be affected then.
I think there is little bit problem in the modal analysis perhaps in mesh or some connection, i'm not sure. I have also mentioned previously my mode shapes in true scale are very disturbing let me show you
Also while meshing I'm not able to see mesh at airfoil and magnet.
As shown only mesh at beam is shown.