"Apple Warns Riders Not To Mount iPhones On Their Motorcycles
To quote the document directly, “exposing your iPhone to high amplitude vibrations within certain frequency ranges, specifically those generated by high-power motorcycle engines, can degrade the performance of the camera system.”
Happened to my iPhone XR. The autofocus caused it to create this weird buzzing sound and the picture was all fuzzy as the lenses zoomed in and out at a very high frequency. Apple repaired it under warranty. I bought a dampening mount for my Quad Lock Holder on all my bikes.