Vortex Sound Research

I purchased my first synth around 2 months ago (boog model d secondhand cause I’m broke) and I’ve been having a ton of fun with it. Recently, however, I’ve began to get this popping/clicking noise at the attack when I input midi. I thought that increasing the attack might mitigate this, but it did nothing. The noise shows up whenever I have any oscillator on and only seems to be impacted by the master out knob- I’ve tested with different outputs so I know it’s not a signal flow problem. Is there anything I can do about this? It’s pretty much rendering the thing unusable for recording right now. Thanks