When I move the Keyframes pane from the the bottom-left panel to the bottom-right, so I can see the timeline and the keyframes at the same time, and try to add a (second) keyframe, it crashes. The bug was happening on 23.05.07 originally and seems to be on 23.05.14, too.
My get-around was to leave Keyframes in the bottom-left panel.
I did not recreate this after trying a couple of times. Maybe there is another factor that is required. Would you be willing to share a screenshot of Shotcut immediately before it crashes? According to your steps, I think you would move the panel, take a screenshot, and then add a keyframe to cause the crash.
Thank you for sharing the video. I was hoping that it would reveal and extra step to help me recreate the problem. I tried to match as many settings and filters as possible. But I still can not recreate it. Hopefully someone else will see this report and find a way to recreate the problem that will also break for a developer.