Hi ​@meatysaurus, thanks for reaching out! 

This sounds related to a bug that’s been flagged by the community in the past: Prototypes flickering black

Are you still having issues with the iOS app? If so, may I ask which apple device and iOS are you using? 

Hi ​@djv I have the same issue when mirroring the prototype on my Figma iOS app. When I play the prototype on desktop, all the videos in the prototype play smoothly. But when I mirrored it on Figma iOS app, the video frame turned black for 1-2 second before starting to play. 

Hi ​@hujiarui, thanks for chiming in here and apologies for the delayed reply! 

Did you check the solution listed on the previous topic I linked to see if that helps?

If not, may I ask which apple device and iOS are you using? With a few more details, we can flag this over to the team to investigate further.