Polivoks filter board Resonance doesn't work in full range

I have a problem with my Shruthi with Polivoks filter board, using YAM 0.5 firmware, that the Resonance range works only from 0 to 30, then after at the value of 31 there seems to be a bit sudden increase, and after that in the whole range (32-63) there is no audible change. Any idea what could be the problem?

Just an update: accidentally the Polivoks Shruthi fell on the floor while preparing for a live show, and the Resonance issue solved – so probably it was some contact issue.