The one is an analog synth, so, it is normal that each voice behave slightly differently. This is what makes the sounds of analog synth lively and interesting.
However, I found that when it comes to filter self-oscillation (turning the filter into a sine tone generator) - the different voices produce different pitches. The manual mentions using the filter in self-oscillation mode, to play is as an oscillator, and avises a filter keyboard tracking of 100% to do so. The problem is not the tracking, but the different voices that will self-oscillate to different frequencies. Which makes it unplayable, as a tuned oscillator.
To reproduce the issue, start from an INIT PATCH, crank the filter resonance to the maximum to make the filter self-oscillate, and then hit one single note, consecutively. You will hear a “pitch” sequence that has a length of 8 or 16 depending on your model. Like a ta-ta-ta-to-to-ta-ti-ti-ta-ta-ta-to-to-ta-ti-ti-…
Can we calibrate the filters manually?