Hello! It turned out to solve this problem with a trick when creating an AVComposition. Namely, when creating AVComposition, I began to use two instead of one AVCompositionTrack in a checkerboard pattern. This solves the problem of not only different fps for neighboring videos, but also a different transform, if it was applied. let videoTracks = [ composition.addMutableTrack(withMediaType: .video, preferredTrackID: kCMPersistentTrackID_Invalid)!, composition.addMutableTrack(withMediaType: .video, preferredTrackID: kCMPersistentTrackID_Invalid)! ] let timeRangeStart: CMTime = .zero for (index, asset) in assets.enumerated() { let videoTrack = videoTracks[index % 2] let assetTrack = asset.tracks(withMediaType: .video).first let timeRange = CMTimeRange(start: .zero, duration: asset.duration) do {     try videoTrack.insertTimeRange( timeRange, of: assetTrack, at: timeRangeStart ) timeRangeStart = timeRangeStart + timeRange.duration } catch { logError() } }