The problem is coherent ratio, set this to 0.

Coherent ratio will lower your render time, but it exchanges flickering on a per-pixel level for flickering across large areas of your image. You can only use coherent ratio in an animation with much higher sample rates, minimum of 500 samples but ...

I created a movie theater scene,
but when I rendered a test animation video, the footage was unusable because lights were flickering/blinking on the walls and everyware.

Video link: https://youtu.be/TpCiDKCcgp4

Lighting sources:
The main screen: is emitting using texture emission.
Mobile phone ...