One of the things that could be happening is your object scale. Be sure you applied the scale of your object. After that, try adjusting your bevel amount. In the video you have it set to 30.1 cm, so that may be too small or perhaps too big, depending on the scale of your object. That’s why it’s important to model to scale or not have the scale values out of whack. If you’re still having trouble, you can share a link with your file so we can help do some troubleshooting.
