Pitched CV going out of range on OSC V/oct

I’m completely new to playing any kind of notes but i’m playing the er301 osc on a midi keyboard and am having issues with the audio sounding like it’s clipping when i send pitched cv to its v/oct input.

I’m using a polyend poly2 module to convert midi to cv and i’ve set it to output 0-5v. the audio isn’t clipping on my my mixer just the characteristic of the sound. Theres no issue playing in lower octave but the cv value represented on the v/oct section in er301 goes out of range once i reach about 3 octaves high on the keyboard. I’m inputting CV via A1

is there anything i can do to fix this?