Brightness of video lowers when going fullscreen in Keynote. HELP

Hey guys, I just finished this presentation which i have to show via zoom call but for some reason Keynotes lowers the brightness of all my videos when playing back in presentation or slide show mode.

The still of the video even on presentation mode looks as the original, it´s only when i click on play that it turns darker. I´ve tried looping or unselecting start movie on click and different options but all the same.

If i play the videos where you edit your slides, brightness works great. I´ve tried different video formats and same. The problem seems to only be only in my MacBooks Keynote since i can play the videos just fine using quicktime or VLC. Also, if i send my presentation to my iphone and open it through the keynote app, it plays back everything as it should. I´ve always used keynotes and this is the first time this has happened to me. I´ve inserted images to show difference in brightness, 1st is as is and 2nd is darkened during playback.

I´m currently running on Big Sur 11.2.3 and version 10.3.9 of Keynote

Hope someone can help,

Thank you