flickering and extrange shadows

Firstly, I have been experiencing flickering issues while rendering my animation project. The rendered frames seem to exhibit an inconsistent and rapid flashing effect, making the final output appear unstable and visually unappealing. I have tried adjusting various settings, such as the anti-aliasing options and frame rates, but unfortunately, the flickering problem persists.

Moreover, I have noticed peculiar shadows being generated during the rendering phase of my animation. These shadows appear distorted or misplaced, creating an unnatural and undesirable effect on the rendered scenes. Despite experimenting with different lighting setups and shadow settings, I have been unable to resolve this issue effectively.