Hello

I bought a used dbx160A and testest it with noise connected to my RME Fireface. It sounded really dull in the high frequencies so i decided to test it with noise and an analyzer. The resulting measuremts are with "bypass" pressed and non-pressed on the dbx.
I found an rolloff in the high end. Its nearly equally with the 1/4 audio jacks and the xlr jacks.
Is it broken? Do you have any tips?
I attache a jpg.
Thank you so much