I had a problem when I pressed CTRL + Z to undo and it suddenly freezes, crashes and when I reopened it, the timeline was a mess. Thankfully it was just the first few clips. On r/shotcut which is a reddit for this app, some people have this problem too last year, but it was never fixed.
What version of Shotcut are you using?
More steps are required because given the information I do not reproduce a problem. There are many variations of undo.
Well, I made some mistakes and wanted to undo a few steps, so I press CTRL+Z a few times, then it was unresponsive. Afterwards, it crashes. When I reopened the app and opened up the auto-save, the first few clips were put somewhere at the middle and end of the timeline.
I think 19.9, I am going to update to check if it is resolved. I’ll keep you guys updated once I check if there is still the same problem.