DJM S-11 knob filters

So here's an annoying problem I'm trying to solve.

Whenever I power off the mixer, the next time I want to use the filter knobs they simply stopped working. Every setting in the FX banks works accordingly, but to be able to use the filters again I have to do a factory reset, and then adjust AGAIN the parameters of the FX banks. 

It's been working absolutely fine until now, so I don't know where does this problem come from, and it is really annoying.

Andy