Problem of sudden volume drop on the headphone preview and pad flashing

Hi, i have a ddj400 I found that during the pre-listening, at times, the volume of the audio in the headphones drastically decreases (both the pre-listening and the mix) and in the meantime the light turns on flashing (second row second column) in both pads under each jog. Sometimes it resets itself, other times you have to unplug and reattach the controller. Follows the print screren of RekorBbox configuration

Rekordbox version 6.5.1

thank you in advance and look forward to it.

Regards

Paolo