Erica Synths Graphic VCO help

Any ideas as to why I'm getting this behaviour would be cool.

So, if I feed a sequence into the volt/octave input that consists of the “C” major scale ie: C D E F G A B C
it will play that back just fine. However if I turn on the VCO’s built in quantiser, set to chromatic, it plays back C sharp D E F G A B C.
I have calibrated the VCO so it’s not that. I’m completely baffled as to why the first C is sharp.

Quantizing already quantized notes leads to a dark portal of mysteries and small voltage offsets.
Add a small +- voltage offset to your input cv and your half step off will be fixed, or migrate.
Depends on how your quantizer rounds up or down when the input is close to a note.

EDITED Today, 04:24