Can you confirm which cv to midi converter you’re using?
I’ve tried two: Expert Sleepers CVM-8 and Befaco CV Thing. Both create cc data that overwhelms the H9000. The developer of CVM-8 indicated that he may add a sample rate control, which could fix the issue.
Re: befaco cv thing, I’m seeing
HiRES MIDI as a menu option in the firmware code. Can you confirm whether you have that enabled / disabled? Perhaps toggling that off will fix the issue.