Mark In and Mark Out still reads same length?

This isn’t an actual issue with me and seems to be more of a bug that is easily worked around.

When I use Video AI to just shorten the length of a video using the Mark In and/or Mark Out tools, the final result on my Windows 11 PC still gives me the original length of the video, even though it has still been edited it down to the length I created.

Is there any reason why this could be happening?