Belt tuning success
After struggling with Core One belt tuning with my Samsung Galaxy S22, and reading Joe's X-post on the topic, I switched to my old iPhone X and found that the resulting frequency given by the iPhone (47Hz) was almost exactly half of that given with the S22 (98Hz), obviously a harmonic issue with the S22 filtering. Retuning with the iPhone was easier and the resulting Y-axis calibration was achieved instantly with minimum head-banging!!! This time, it was necessary to re-check each side after adjustment to fine-tune the results, which were consistent. 🥂
RE: Belt tuning success
I had to take off my iPhone cover clean the microphone cover with a soft toothbrush then turn off all surrounding sound including any fans in the room place the microphone as close to the belt as I can then it started working perfectly when following Prusa's latest belt tuning instructions.