Slider: Cutoff Filter not working

Hi everyone, My name is Daniel and I am new here.
Hope anyone can help me with this.I bought a second hand Akai Mpc 1000, and installed free JJos.

I love it! Everything seems working fine, but one thing is apparently not working:

When I go into slider Mode, and select Parameter Cutoff 1+2 or Cutoff 1 or Cutoff 2 or FILTER in Note on mode. the slider doesn't affect the sound (no cutoff modulation can be heard).

I don't have any problem with other parameters such as Tune, Levels and Pan, they work fine.

Anyone can guess why it doesn't work?
Could it be a hardware problem?

Thanks. Have a nice day,
Dan.

yup, choose filter in program mode.