Undo and redo Failure after instantiation

this.gantt = Gantt.getGanttInstance(); gantt After instantiation undo、order_branch and redo Invalid

Hello,
Unfortunately, I couldn’t reproduce the issue.
Please, send me a demo project where I can reproduce the issue.

Hello,
Thank you for sending me the screenshot. Unfortunately, that doesn’t help. I need to reproduce the issue in a demo project. It is not necessary to send your project. You can create a new test project and reproduce the issue there.