UE4.22 - Level FPS drops from 60 FPS to 8 FPS after playing a video through BP, why?

Hi, my intro video (24mb & precashed) and menu widget was loading in level 1 at 60 FPS; after “play” button is pressed, level 2 is loaded with the game (this is the common process you find in any tutorial, sepparated levels for menu and game), BUT… by doing this, level 2 opens with half FPS, from 30 FPS (original FPS or this level) to 15 FPS or less, instead if ignore level 1 and click play at level 2(game), FPS stays at 30.

For this reasson i thought: maybe i should start main menu and intro video at Level 2 and simply hide them after press play and posses player… It worked fine, but now the whole game (Level 2) is afected… Intro video starts at 8 FPS or less, menu starts at 10 FPS and then game starts at 12 FPS…now everything is worst.

Why game FPS is affected by mixing it with media? videos are not even 3D assets but they still play slowr with less FPS.
Why loading a level through BP´s node “Open Level” makes that level to load with half FPS?