2 of my media players in the scene work, but the rest doesnt work

So I am still very new to UE5, but I just wanted to create a sequence where I showcase a few of my projects from the year 2024.

When I compile the blueprint which causes everything to play it works.
However, when I click on the play button or render it out the last 4 are frozen and dont work at all.

Al 6 of the media players are setup the exact same, so I am not sure why only 2 of them work.