Hi vitbit!
You may need to set your audio input device to use a sample rate of 44.1 khz to get the best results with Waveclock. You can adjust this with the Audio MIDI Setup utility on your Mac.
(We have a branch of VDMX that fixes this by converting the incoming audio to 44.1 khz on the fly if needed, but it is part of a lot of other audio related changed (that fix similar sorts of edge cases) that we haven’t put into public production yet.)
If that isn’t the case, please send us a bug report via the Help menu!