My Werkstatt’s oscillator isn’t in tune when I connect to external an CV Source. Is mine broken?

Your Werkstatt is not broken. Because there can be variances in scaling between different CV instruments, you might notice your Werkstatt ends up out of tune when connected to some volt per octave CV sources.  If you experience this behavior, you can perform the calibration in this video (text instructions here) to ensure your Werkstatt responds well to the particular control source you choose to use.