The cut-off frequency concept is :
After this frequency -in the earthquake case 33 Hz- no more important dynamic effect.
Thats right.

My standard spectrums input ends at cut-off frequency.
So i dont have this problem.

In your case spectrum input end at 10 Hz.
Nevertheless Caesar calculate eigenvalues until 33 Hz.
Our question are :
Which acceleration take Caesar to calculate missing mass response by extracted or spectrum in your example ?
More then this which accelarations take Caesar for the eigenvalues greater 10 Hz until 33 Hz ?