I have the same problem. Instead of cropping the top, it simply moves the whole video frame upward. There is a solution for this, just move the video frame downwards to the edge of the frame, then use the crop top tool to move the video back up to where the piano is lined up with the saber. This worked for me.
The Crop Top feature has been slightly updated - but in all testing, it seems to be confirmed to currently be working as it should be.
In the newer version, the video will move upwards as the video is cropped, to keep the top of the video aligned with the top of the keyboard. This is because most users are trying to align the top of the video with the top of the keyboard. It also makes it easier for the app to keep things aligned if the user renders at different aspect ratios.
If you want the video to still be lower, you would use the position feature to move it lower after cropping.
If you think you are still experiencing an issue with this, please upload a screen video capture of the issue so that I can see exactly what’s happening on your device.