Adobe Captivate interactive video button delay

am trying to create an interactive video. The length of my video is 4 minutes, and I have placed 14 buttons. The buttons are designed to appear on the screen and automatically pause the video. I input the specific seconds; for instance, I want it to pause at 78 seconds. However, when I play it, the video pauses at 79 seconds. The button properties are set with “Appear after 78 seconds” and “Pause after 0.5 seconds.” When I play the video, it pauses at 79 seconds.