Filter sounds off on certain keys (Sub 37)

[FunkDojo]

Hey everybody. I got a Subsequent 37 some time ago and never had an issue with it, and now I've come back to it after a few months of it sitting on a desk not making music and it's behaving weirdly. I've tried to google around for similar issues but come up short, so I figured I'd ask here.

Much like the title suggests, the problem I'm having is that certain notes sound off. It's consistent on the note G across all octaves except the bottom couple, but also appears elsewhere across the range although more subtly. Spontaneously it feels related to the filter somehow as there's a certain span around the middle of the pitch range where on the lower of the two Gs, it sounds like the resonance is cranked up at a pretty high cutoff so you can hear the bottom end drop out and the note rings out pretty weakly as a result, and on the next G up, the resonance peak is lower down in the mids and the note appears way louder than neighboring notes.

Unfortunately I'm not in a position to record it and post an audio example currently but I figured I would post it to see if anybody recognizes the issue anyway, and if not I'll post something when I can. I have run the calibration routines available in the firmware but nothing's made a difference. Any input is very welcome.

[Montfrooij]

I have no clue what is the problem.
My first question was if you could record something.
Maybe even via your telephone and share it on youtube or so.