Black frames in iMovie
So, I imported videos that have little lags, when I see them in my iPhone or even in iMovie they look fine, the problem comes when I put them in the editing bar and zoom in black frames appear when the lagging happens, I can't even trim them cause they don't last that long, also when I don't manipulate the videos they look fine, when I speed them up or down, the black frames become visible in the preview.
What I did was screen record the videos and now they look fine, I know it's not the best solution but it worked
iPhone SE, iOS 12