This is often a frame rate mismatch. Ensure your project setting (e.g., 1080p 30fps) matches the footage imported.
Keep the frame rate matching your original footage (e.g., 29.97 fps or 25 fps). Import the newly converted file into Pinnacle Studio 14.
Here are the direct sources for the codec solutions discussed:
Use VLC Media Player or Handbrake to convert your MP4 files into a high-quality MPEG-2 or AVI format.
A legal copy of Pinnacle Studio 24 costs less than the time wasted chasing broken MPEG-4 hot downloads for Studio 14.