Can't change duration of Illustrator vector files
I am just going to start off by saying I am just learning After Effects, so bear with me. I am creating a vector animation in AE but made all my vectors in AI. I may have made the mistake of creating all my frames in one big Illustrator file with multiple art boards. I saved the AI files so the art boards are separated into different .ai files. I imported one of the .ai files (one frame with layers) into AE it shows only that frame and the including layers. However, when I try to change the duration of the frame, it only shows the frame for a split second. If the video keeps playing, then other frames from different artboards start showing for a split second. These frames that show up for just a split second shouldn't be one this frame because they are from different art boards that shouldn't be saved with this .ai file. It seems as though all the other artboards are still connected to the file in some way. If my explanation didn't make sense, here's a video that shows what's happening.

