The area in the red box keeps shaking
It’s likely caused by z-fighting. When you place two planes / faces very close to each other (and they are facing the same direction) - the renderer may have issues determining what should be rendered first.
Depending on the camera angle the answer may be different - hence, as long as you keep moving the camera, the jittery effect appears.
Put the model on this website, it will not shake, but I looked at the source code of this website, did not find anything special
those thin plates are too close or there’s a modelling error ,