I bought a Bittle on Amazon and generally I'm impressed. But the right hind leg seems to have a problem. It gives way when walking, leading to Bittle walking in circles. Is that a defect or can it be calibrated somehow? See: https://www.youtube.com/watch?v=5M3gM2HJCXg I contacted support via email but got no answer, does anyone know how the response times are? TIA