How to smooth the FRF curve?

Hi all, I have obtained FRF curve with calculating cross power of output/input and auto power spectral density of input/input using cpsd function. The resulting curve has additional small peaks which can be seen when I zoom in the parts of the curve. Here you can see the resulting curve.

For instance, if I zoom in the third maximum peak, you can see the additional small peaks. These additional peaks are also present along the whole curve nut just at the location of max peaks.

Is there any way how I could remove these peaks in MATLAB? Is it normal that MATLAB gives me the resulting curve as this? Do you have any suggestions what could I do to obtain a smoother curve? Thanks!