DSP Robotics Support

I'm trying to get stable pitch tracking for low frequencies (40-300Hz) in order to monitor selected peaks above the fundamental (I'm using recent Martin's pitch tracking module). But no matter what I do - I can't stabilize the peak detection/appearance within detectable range (and accuracy). I don't know, maybe it should be different pitch detection method? (acceptable would be slower but more stable). Can someone help?

I made a "smart" green buffer, that seems to do the job. However I don't know if this is the greatest idea. Or maybe it can be simplified?

Made different buffer.