I’m going to assume the shots of Bee running in the forest is connected with the Starscream scene. Can’t tell which Alt mode Bee has in that scene. Could be they both arrive on earth before the F-15 get introduced, which would explain Starscream adopting the F-4 at that time. At least that is my running theory
Then the story picks up later with both Bee and Screamer having proper alt modes.
At least thats my hope.